Issue #29371: merge with 3.5

1 files changed, 743 insertions, 332 deletions

diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c
index f419cb22ef..291920dc0f 100644
--- a/Modules/_datetimemodule.c
+++ b/Modules/_datetimemodule.c
@@ -56,6 +56,7 @@ class datetime.datetime "PyDateTime_DateTime *" "&PyDateTime_DateTimeType"
 #define DATE_GET_MINUTE         PyDateTime_DATE_GET_MINUTE
 #define DATE_GET_SECOND         PyDateTime_DATE_GET_SECOND
 #define DATE_GET_MICROSECOND    PyDateTime_DATE_GET_MICROSECOND
+#define DATE_GET_FOLD           PyDateTime_DATE_GET_FOLD
 
 /* Date accessors for date and datetime. */
 #define SET_YEAR(o, v)          (((o)->data[0] = ((v) & 0xff00) >> 8), \
@@ -71,12 +72,14 @@ class datetime.datetime "PyDateTime_DateTime *" "&PyDateTime_DateTimeType"
     (((o)->data[7] = ((v) & 0xff0000) >> 16), \
      ((o)->data[8] = ((v) & 0x00ff00) >> 8), \
      ((o)->data[9] = ((v) & 0x0000ff)))
+#define DATE_SET_FOLD(o, v)   (PyDateTime_DATE_GET_FOLD(o) = (v))
 
 /* Time accessors for time. */
 #define TIME_GET_HOUR           PyDateTime_TIME_GET_HOUR
 #define TIME_GET_MINUTE         PyDateTime_TIME_GET_MINUTE
 #define TIME_GET_SECOND         PyDateTime_TIME_GET_SECOND
 #define TIME_GET_MICROSECOND    PyDateTime_TIME_GET_MICROSECOND
+#define TIME_GET_FOLD           PyDateTime_TIME_GET_FOLD
 #define TIME_SET_HOUR(o, v)     (PyDateTime_TIME_GET_HOUR(o) = (v))
 #define TIME_SET_MINUTE(o, v)   (PyDateTime_TIME_GET_MINUTE(o) = (v))
 #define TIME_SET_SECOND(o, v)   (PyDateTime_TIME_GET_SECOND(o) = (v))
@@ -84,6 +87,7 @@ class datetime.datetime "PyDateTime_DateTime *" "&PyDateTime_DateTimeType"
     (((o)->data[3] = ((v) & 0xff0000) >> 16), \
      ((o)->data[4] = ((v) & 0x00ff00) >> 8), \
      ((o)->data[5] = ((v) & 0x0000ff)))
+#define TIME_SET_FOLD(o, v)   (PyDateTime_TIME_GET_FOLD(o) = (v))
 
 /* Delta accessors for timedelta. */
 #define GET_TD_DAYS(o)          (((PyDateTime_Delta *)(o))->days)
@@ -184,12 +188,12 @@ divide_nearest(PyObject *m, PyObject *n)
  * and the number of days before that month in the same year.  These
  * are correct for non-leap years only.
  */
-static int _days_in_month[] = {
+static const int _days_in_month[] = {
     0, /* unused; this vector uses 1-based indexing */
     31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
 };
 
-static int _days_before_month[] = {
+static const int _days_before_month[] = {
     0, /* unused; this vector uses 1-based indexing */
     0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
 };
@@ -417,7 +421,7 @@ check_date_args(int year, int month, int day)
  * aren't, raise ValueError and return -1.
  */
 static int
-check_time_args(int h, int m, int s, int us)
+check_time_args(int h, int m, int s, int us, int fold)
 {
     if (h < 0 || h > 23) {
         PyErr_SetString(PyExc_ValueError,
@@ -439,6 +443,11 @@ check_time_args(int h, int m, int s, int us)
                         "microsecond must be in 0..999999");
         return -1;
     }
+    if (fold != 0 && fold != 1) {
+        PyErr_SetString(PyExc_ValueError,
+                        "fold must be either 0 or 1");
+        return -1;
+    }
     return 0;
 }
 
@@ -674,8 +683,8 @@ new_date_ex(int year, int month, int day, PyTypeObject *type)
 
 /* Create a datetime instance with no range checking. */
 static PyObject *
-new_datetime_ex(int year, int month, int day, int hour, int minute,
-             int second, int usecond, PyObject *tzinfo, PyTypeObject *type)
+new_datetime_ex2(int year, int month, int day, int hour, int minute,
+                 int second, int usecond, PyObject *tzinfo, int fold, PyTypeObject *type)
 {
     PyDateTime_DateTime *self;
     char aware = tzinfo != Py_None;
@@ -692,18 +701,27 @@ new_datetime_ex(int year, int month, int day, int hour, int minute,
             Py_INCREF(tzinfo);
             self->tzinfo = tzinfo;
         }
+        DATE_SET_FOLD(self, fold);
     }
     return (PyObject *)self;
 }
 
-#define new_datetime(y, m, d, hh, mm, ss, us, tzinfo)           \
-    new_datetime_ex(y, m, d, hh, mm, ss, us, tzinfo,            \
+static PyObject *
+new_datetime_ex(int year, int month, int day, int hour, int minute,
+                int second, int usecond, PyObject *tzinfo, PyTypeObject *type)
+{
+    return new_datetime_ex2(year, month, day, hour, minute, second, usecond,
+                            tzinfo, 0, type);
+}
+
+#define new_datetime(y, m, d, hh, mm, ss, us, tzinfo, fold) \
+    new_datetime_ex2(y, m, d, hh, mm, ss, us, tzinfo, fold, \
                     &PyDateTime_DateTimeType)
 
 /* Create a time instance with no range checking. */
 static PyObject *
-new_time_ex(int hour, int minute, int second, int usecond,
-            PyObject *tzinfo, PyTypeObject *type)
+new_time_ex2(int hour, int minute, int second, int usecond,
+             PyObject *tzinfo, int fold, PyTypeObject *type)
 {
     PyDateTime_Time *self;
     char aware = tzinfo != Py_None;
@@ -720,12 +738,20 @@ new_time_ex(int hour, int minute, int second, int usecond,
             Py_INCREF(tzinfo);
             self->tzinfo = tzinfo;
         }
+        TIME_SET_FOLD(self, fold);
     }
     return (PyObject *)self;
 }
 
-#define new_time(hh, mm, ss, us, tzinfo)                \
-    new_time_ex(hh, mm, ss, us, tzinfo, &PyDateTime_TimeType)
+static PyObject *
+new_time_ex(int hour, int minute, int second, int usecond,
+            PyObject *tzinfo, PyTypeObject *type)
+{
+    return new_time_ex2(hour, minute, second, usecond, tzinfo, 0, type);
+}
+
+#define new_time(hh, mm, ss, us, tzinfo, fold)                       \
+    new_time_ex2(hh, mm, ss, us, tzinfo, fold, &PyDateTime_TimeType)
 
 /* Create a timedelta instance.  Normalize the members iff normalize is
  * true.  Passing false is a speed optimization, if you know for sure
@@ -873,7 +899,7 @@ get_tzinfo_member(PyObject *self)
  * this returns NULL.  Else result is returned.
  */
 static PyObject *
-call_tzinfo_method(PyObject *tzinfo, char *name, PyObject *tzinfoarg)
+call_tzinfo_method(PyObject *tzinfo, const char *name, PyObject *tzinfoarg)
 {
     PyObject *offset;
 
@@ -887,10 +913,10 @@ call_tzinfo_method(PyObject *tzinfo, char *name, PyObject *tzinfoarg)
     if (offset == Py_None || offset == NULL)
         return offset;
     if (PyDelta_Check(offset)) {
-        if (GET_TD_MICROSECONDS(offset) != 0 || GET_TD_SECONDS(offset) % 60 != 0) {
+        if (GET_TD_MICROSECONDS(offset) != 0) {
             Py_DECREF(offset);
             PyErr_Format(PyExc_ValueError, "offset must be a timedelta"
-                         " representing a whole number of minutes");
+                         " representing a whole number of seconds");
             return NULL;
         }
         if ((GET_TD_DAYS(offset) == -1 && GET_TD_SECONDS(offset) == 0) ||
@@ -1002,6 +1028,30 @@ append_keyword_tzinfo(PyObject *repr, PyObject *tzinfo)
     return repr;
 }
 
+/* repr is like "someclass(arg1, arg2)".  If fold isn't 0,
+ * stuff
+ *     ", fold=" + repr(tzinfo)
+ * before the closing ")".
+ */
+static PyObject *
+append_keyword_fold(PyObject *repr, int fold)
+{
+    PyObject *temp;
+
+    assert(PyUnicode_Check(repr));
+    if (fold == 0)
+        return repr;
+    /* Get rid of the trailing ')'. */
+    assert(PyUnicode_READ_CHAR(repr, PyUnicode_GET_LENGTH(repr)-1) == ')');
+    temp = PyUnicode_Substring(repr, 0, PyUnicode_GET_LENGTH(repr) - 1);
+    Py_DECREF(repr);
+    if (temp == NULL)
+        return NULL;
+    repr = PyUnicode_FromFormat("%U, fold=%d)", temp, fold);
+    Py_DECREF(temp);
+    return repr;
+}
+
 /* ---------------------------------------------------------------------------
  * String format helpers.
  */
@@ -1009,10 +1059,10 @@ append_keyword_tzinfo(PyObject *repr, PyObject *tzinfo)
 static PyObject *
 format_ctime(PyDateTime_Date *date, int hours, int minutes, int seconds)
 {
-    static const char *DayNames[] = {
+    static const char * const DayNames[] = {
         "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"
     };
-    static const char *MonthNames[] = {
+    static const char * const MonthNames[] = {
         "Jan", "Feb", "Mar", "Apr", "May", "Jun",
         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
     };
@@ -1057,10 +1107,8 @@ format_utcoffset(char *buf, size_t buflen, const char *sep,
     }
     /* Offset is normalized, so it is negative if days < 0 */
     if (GET_TD_DAYS(offset) < 0) {
-        PyObject *temp = offset;
         sign = '-';
-        offset = delta_negative((PyDateTime_Delta *)offset);
-        Py_DECREF(temp);
+        Py_SETREF(offset, delta_negative((PyDateTime_Delta *)offset));
         if (offset == NULL)
             return -1;
     }
@@ -1072,10 +1120,11 @@ format_utcoffset(char *buf, size_t buflen, const char *sep,
     Py_DECREF(offset);
     minutes = divmod(seconds, 60, &seconds);
     hours = divmod(minutes, 60, &minutes);
-    assert(seconds == 0);
-    /* XXX ignore sub-minute data, currently not allowed. */
-    PyOS_snprintf(buf, buflen, "%c%02d%s%02d", sign, hours, sep, minutes);
-
+    if (seconds == 0)
+        PyOS_snprintf(buf, buflen, "%c%02d%s%02d", sign, hours, sep, minutes);
+    else
+        PyOS_snprintf(buf, buflen, "%c%02d%s%02d%s%02d", sign, hours,
+                      sep, minutes, sep, seconds);
     return 0;
 }
 
@@ -1170,7 +1219,7 @@ wrap_strftime(PyObject *object, PyObject *format, PyObject *timetuple,
     assert(object && format && timetuple);
     assert(PyUnicode_Check(format));
     /* Convert the input format to a C string and size */
-    pin = _PyUnicode_AsStringAndSize(format, &flen);
+    pin = PyUnicode_AsUTF8AndSize(format, &flen);
     if (!pin)
         return NULL;
 
@@ -1238,7 +1287,7 @@ wrap_strftime(PyObject *object, PyObject *format, PyObject *timetuple,
             }
             assert(Zreplacement != NULL);
             assert(PyUnicode_Check(Zreplacement));
-            ptoappend = _PyUnicode_AsStringAndSize(Zreplacement,
+            ptoappend = PyUnicode_AsUTF8AndSize(Zreplacement,
                                                   &ntoappend);
             if (ptoappend == NULL)
                 goto Done;
@@ -1323,7 +1372,7 @@ time_time(void)
     if (time != NULL) {
         _Py_IDENTIFIER(time);
 
-        result = _PyObject_CallMethodId(time, &PyId_time, "()");
+        result = _PyObject_CallMethodId(time, &PyId_time, NULL);
         Py_DECREF(time);
     }
     return result;
@@ -2307,7 +2356,7 @@ static PyMethodDef delta_methods[] = {
     {NULL,      NULL},
 };
 
-static char delta_doc[] =
+static const char delta_doc[] =
 PyDoc_STR("Difference between two datetime values.");
 
 static PyNumberMethods delta_as_number = {
@@ -2462,27 +2511,19 @@ date_new(PyTypeObject *type, PyObject *args, PyObject *kw)
 static PyObject *
 date_local_from_object(PyObject *cls, PyObject *obj)
 {
-    struct tm *tm;
+    struct tm tm;
     time_t t;
 
     if (_PyTime_ObjectToTime_t(obj, &t, _PyTime_ROUND_FLOOR) == -1)
         return NULL;
 
-    tm = localtime(&t);
-    if (tm == NULL) {
-        /* unconvertible time */
-#ifdef EINVAL
-        if (errno == 0)
-            errno = EINVAL;
-#endif
-        PyErr_SetFromErrno(PyExc_OSError);
+    if (_PyTime_localtime(t, &tm) != 0)
         return NULL;
-    }
 
     return PyObject_CallFunction(cls, "iii",
-                                 tm->tm_year + 1900,
-                                 tm->tm_mon + 1,
-                                 tm->tm_mday);
+                                 tm.tm_year + 1900,
+                                 tm.tm_mon + 1,
+                                 tm.tm_mday);
 }
 
 /* Return new date from current time.
@@ -2648,7 +2689,7 @@ date_isoformat(PyDateTime_Date *self)
 static PyObject *
 date_str(PyDateTime_Date *self)
 {
-    return _PyObject_CallMethodId((PyObject *)self, &PyId_isoformat, "()");
+    return _PyObject_CallMethodId((PyObject *)self, &PyId_isoformat, NULL);
 }
 
 
@@ -2674,7 +2715,7 @@ date_strftime(PyDateTime_Date *self, PyObject *args, PyObject *kw)
                                       &format))
         return NULL;
 
-    tuple = _PyObject_CallMethodId((PyObject *)self, &PyId_timetuple, "()");
+    tuple = _PyObject_CallMethodId((PyObject *)self, &PyId_timetuple, NULL);
     if (tuple == NULL)
         return NULL;
     result = wrap_strftime((PyObject *)self, format, tuple,
@@ -2786,9 +2827,10 @@ static PyObject *date_getstate(PyDateTime_Date *self);
 static Py_hash_t
 date_hash(PyDateTime_Date *self)
 {
-    if (self->hashcode == -1)
+    if (self->hashcode == -1) {
         self->hashcode = generic_hash(
             (unsigned char *)self->data, _PyDateTime_DATE_DATASIZE);
+    }
 
     return self->hashcode;
 }
@@ -2886,7 +2928,7 @@ static PyMethodDef date_methods[] = {
     {NULL,      NULL}
 };
 
-static char date_doc[] =
+static const char date_doc[] =
 PyDoc_STR("date(year, month, day) --> date object");
 
 static PyNumberMethods date_as_number = {
@@ -3047,10 +3089,8 @@ tzinfo_fromutc(PyDateTime_TZInfo *self, PyObject *dt)
     if (dst == Py_None)
         goto Inconsistent;
     if (delta_bool((PyDateTime_Delta *)dst) != 0) {
-        PyObject *temp = result;
-        result = add_datetime_timedelta((PyDateTime_DateTime *)result,
-                                        (PyDateTime_Delta *)dst, 1);
-        Py_DECREF(temp);
+        Py_SETREF(result, add_datetime_timedelta((PyDateTime_DateTime *)result,
+                                                 (PyDateTime_Delta *)dst, 1));
         if (result == NULL)
             goto Fail;
     }
@@ -3080,37 +3120,34 @@ Fail:
 static PyObject *
 tzinfo_reduce(PyObject *self)
 {
-    PyObject *args, *state, *tmp;
+    PyObject *args, *state;
     PyObject *getinitargs, *getstate;
     _Py_IDENTIFIER(__getinitargs__);
     _Py_IDENTIFIER(__getstate__);
 
-    tmp = PyTuple_New(0);
-    if (tmp == NULL)
-        return NULL;
-
     getinitargs = _PyObject_GetAttrId(self, &PyId___getinitargs__);
     if (getinitargs != NULL) {
-        args = PyObject_CallObject(getinitargs, tmp);
+        args = _PyObject_CallNoArg(getinitargs);
         Py_DECREF(getinitargs);
         if (args == NULL) {
-            Py_DECREF(tmp);
             return NULL;
         }
     }
     else {
         PyErr_Clear();
-        args = tmp;
-        Py_INCREF(args);
+
+        args = PyTuple_New(0);
+        if (args == NULL) {
+            return NULL;
+        }
     }
 
     getstate = _PyObject_GetAttrId(self, &PyId___getstate__);
     if (getstate != NULL) {
-        state = PyObject_CallObject(getstate, tmp);
+        state = _PyObject_CallNoArg(getstate);
         Py_DECREF(getstate);
         if (state == NULL) {
             Py_DECREF(args);
-            Py_DECREF(tmp);
             return NULL;
         }
     }
@@ -3119,13 +3156,12 @@ tzinfo_reduce(PyObject *self)
         PyErr_Clear();
         state = Py_None;
         dictptr = _PyObject_GetDictPtr(self);
-        if (dictptr && *dictptr && PyDict_Size(*dictptr))
+        if (dictptr && *dictptr && PyDict_Size(*dictptr)) {
             state = *dictptr;
+        }
         Py_INCREF(state);
     }
 
-    Py_DECREF(tmp);
-
     if (state == Py_None) {
         Py_DECREF(state);
         return Py_BuildValue("(ON)", Py_TYPE(self), args);
@@ -3155,7 +3191,7 @@ static PyMethodDef tzinfo_methods[] = {
     {NULL, NULL}
 };
 
-static char tzinfo_doc[] =
+static const char tzinfo_doc[] =
 PyDoc_STR("Abstract base class for time zone info objects.");
 
 static PyTypeObject PyDateTime_TZInfoType = {
@@ -3287,6 +3323,11 @@ timezone_str(PyDateTime_TimeZone *self)
         Py_INCREF(self->name);
         return self->name;
     }
+    if ((PyObject *)self == PyDateTime_TimeZone_UTC ||
+           (GET_TD_DAYS(self->offset) == 0 &&
+            GET_TD_SECONDS(self->offset) == 0 &&
+            GET_TD_MICROSECONDS(self->offset) == 0))
+        return PyUnicode_FromString("UTC");
     /* Offset is normalized, so it is negative if days < 0 */
     if (GET_TD_DAYS(self->offset) < 0) {
         sign = '-';
@@ -3382,7 +3423,7 @@ static PyMethodDef timezone_methods[] = {
     {NULL, NULL}
 };
 
-static char timezone_doc[] =
+static const char timezone_doc[] =
 PyDoc_STR("Fixed offset from UTC implementation of tzinfo.");
 
 static PyTypeObject PyDateTime_TimeZoneType = {
@@ -3466,12 +3507,19 @@ time_tzinfo(PyDateTime_Time *self, void *unused)
     return result;
 }
 
+static PyObject *
+time_fold(PyDateTime_Time *self, void *unused)
+{
+    return PyLong_FromLong(TIME_GET_FOLD(self));
+}
+
 static PyGetSetDef time_getset[] = {
     {"hour",        (getter)time_hour},
     {"minute",      (getter)time_minute},
     {"second",      (getter)py_time_second},
     {"microsecond", (getter)time_microsecond},
-    {"tzinfo",          (getter)time_tzinfo},
+    {"tzinfo",      (getter)time_tzinfo},
+    {"fold",        (getter)time_fold},
     {NULL}
 };
 
@@ -3480,7 +3528,7 @@ static PyGetSetDef time_getset[] = {
  */
 
 static char *time_kws[] = {"hour", "minute", "second", "microsecond",
-                           "tzinfo", NULL};
+                           "tzinfo", "fold", NULL};
 
 static PyObject *
 time_new(PyTypeObject *type, PyObject *args, PyObject *kw)
@@ -3492,13 +3540,14 @@ time_new(PyTypeObject *type, PyObject *args, PyObject *kw)
     int second = 0;
     int usecond = 0;
     PyObject *tzinfo = Py_None;
+    int fold = 0;
 
     /* Check for invocation from pickle with __getstate__ state */
     if (PyTuple_GET_SIZE(args) >= 1 &&
         PyTuple_GET_SIZE(args) <= 2 &&
         PyBytes_Check(state = PyTuple_GET_ITEM(args, 0)) &&
         PyBytes_GET_SIZE(state) == _PyDateTime_TIME_DATASIZE &&
-        ((unsigned char) (PyBytes_AS_STRING(state)[0])) < 24)
+        (0x7F & ((unsigned char) (PyBytes_AS_STRING(state)[0]))) < 24)
     {
         PyDateTime_Time *me;
         char aware;
@@ -3523,19 +3572,26 @@ time_new(PyTypeObject *type, PyObject *args, PyObject *kw)
                 Py_INCREF(tzinfo);
                 me->tzinfo = tzinfo;
             }
+            if (pdata[0] & (1 << 7)) {
+                me->data[0] -= 128;
+                me->fold = 1;
+            }
+            else {
+                me->fold = 0;
+            }
         }
         return (PyObject *)me;
     }
 
-    if (PyArg_ParseTupleAndKeywords(args, kw, "|iiiiO", time_kws,
+    if (PyArg_ParseTupleAndKeywords(args, kw, "|iiiiO$i", time_kws,
                                     &hour, &minute, &second, &usecond,
-                                    &tzinfo)) {
-        if (check_time_args(hour, minute, second, usecond) < 0)
+                                    &tzinfo, &fold)) {
+        if (check_time_args(hour, minute, second, usecond, fold) < 0)
             return NULL;
         if (check_tzinfo_subclass(tzinfo) < 0)
             return NULL;
-        self = new_time_ex(hour, minute, second, usecond, tzinfo,
-                           type);
+        self = new_time_ex2(hour, minute, second, usecond, tzinfo, fold,
+                            type);
     }
     return self;
 }
@@ -3585,6 +3641,7 @@ time_repr(PyDateTime_Time *self)
     int m = TIME_GET_MINUTE(self);
     int s = TIME_GET_SECOND(self);
     int us = TIME_GET_MICROSECOND(self);
+    int fold = TIME_GET_FOLD(self);
     PyObject *result = NULL;
 
     if (us)
@@ -3597,33 +3654,68 @@ time_repr(PyDateTime_Time *self)
         result = PyUnicode_FromFormat("%s(%d, %d)", type_name, h, m);
     if (result != NULL && HASTZINFO(self))
         result = append_keyword_tzinfo(result, self->tzinfo);
+    if (result != NULL && fold)
+        result = append_keyword_fold(result, fold);
     return result;
 }
 
 static PyObject *
 time_str(PyDateTime_Time *self)
 {
-    return _PyObject_CallMethodId((PyObject *)self, &PyId_isoformat, "()");
+    return _PyObject_CallMethodId((PyObject *)self, &PyId_isoformat, NULL);
 }
 
 static PyObject *
-time_isoformat(PyDateTime_Time *self, PyObject *unused)
+time_isoformat(PyDateTime_Time *self, PyObject *args, PyObject *kw)
 {
     char buf[100];
+    char *timespec = NULL;
+    static char *keywords[] = {"timespec", NULL};
     PyObject *result;
     int us = TIME_GET_MICROSECOND(self);
+    static char *specs[][2] = {
+        {"hours", "%02d"},
+        {"minutes", "%02d:%02d"},
+        {"seconds", "%02d:%02d:%02d"},
+        {"milliseconds", "%02d:%02d:%02d.%03d"},
+        {"microseconds", "%02d:%02d:%02d.%06d"},
+    };
+    size_t given_spec;
 
-    if (us)
-        result = PyUnicode_FromFormat("%02d:%02d:%02d.%06d",
-                                      TIME_GET_HOUR(self),
-                                      TIME_GET_MINUTE(self),
-                                      TIME_GET_SECOND(self),
-                                      us);
-    else
-        result = PyUnicode_FromFormat("%02d:%02d:%02d",
-                                      TIME_GET_HOUR(self),
-                                      TIME_GET_MINUTE(self),
-                                      TIME_GET_SECOND(self));
+    if (!PyArg_ParseTupleAndKeywords(args, kw, "|s:isoformat", keywords, &timespec))
+        return NULL;
+
+    if (timespec == NULL || strcmp(timespec, "auto") == 0) {
+        if (us == 0) {
+            /* seconds */
+            given_spec = 2;
+        }
+        else {
+            /* microseconds */
+            given_spec = 4;
+        }
+    }
+    else {
+        for (given_spec = 0; given_spec < Py_ARRAY_LENGTH(specs); given_spec++) {
+            if (strcmp(timespec, specs[given_spec][0]) == 0) {
+                if (given_spec == 3) {
+                    /* milliseconds */
+                    us = us / 1000;
+                }
+                break;
+            }
+        }
+    }
+
+    if (given_spec == Py_ARRAY_LENGTH(specs)) {
+        PyErr_Format(PyExc_ValueError, "Unknown timespec value");
+        return NULL;
+    }
+    else {
+        result = PyUnicode_FromFormat(specs[given_spec][1],
+                                      TIME_GET_HOUR(self), TIME_GET_MINUTE(self),
+                                      TIME_GET_SECOND(self), us);
+    }
 
     if (result == NULL || !HASTZINFO(self) || self->tzinfo == Py_None)
         return result;
@@ -3750,9 +3842,23 @@ static Py_hash_t
 time_hash(PyDateTime_Time *self)
 {
     if (self->hashcode == -1) {
-        PyObject *offset;
-
-        offset = time_utcoffset((PyObject *)self, NULL);
+        PyObject *offset, *self0;
+        if (TIME_GET_FOLD(self)) {
+            self0 = new_time_ex2(TIME_GET_HOUR(self),
+                                 TIME_GET_MINUTE(self),
+                                 TIME_GET_SECOND(self),
+                                 TIME_GET_MICROSECOND(self),
+                                 HASTZINFO(self) ? self->tzinfo : Py_None,
+                                 0, Py_TYPE(self));
+            if (self0 == NULL)
+                return -1;
+        }
+        else {
+            self0 = (PyObject *)self;
+            Py_INCREF(self0);
+        }
+        offset = time_utcoffset(self0, NULL);
+        Py_DECREF(self0);
 
         if (offset == NULL)
             return -1;
@@ -3798,15 +3904,24 @@ time_replace(PyDateTime_Time *self, PyObject *args, PyObject *kw)
     int ss = TIME_GET_SECOND(self);
     int us = TIME_GET_MICROSECOND(self);
     PyObject *tzinfo = HASTZINFO(self) ? self->tzinfo : Py_None;
+    int fold = TIME_GET_FOLD(self);
 
-    if (! PyArg_ParseTupleAndKeywords(args, kw, "|iiiiO:replace",
+    if (! PyArg_ParseTupleAndKeywords(args, kw, "|iiiiO$i:replace",
                                       time_kws,
-                                      &hh, &mm, &ss, &us, &tzinfo))
+                                      &hh, &mm, &ss, &us, &tzinfo, &fold))
         return NULL;
     tuple = Py_BuildValue("iiiiO", hh, mm, ss, us, tzinfo);
     if (tuple == NULL)
         return NULL;
     clone = time_new(Py_TYPE(self), tuple, NULL);
+    if (clone != NULL) {
+        if (fold != 0 && fold != 1) {
+            PyErr_SetString(PyExc_ValueError,
+                            "fold must be either 0 or 1");
+            return NULL;
+        }
+        TIME_SET_FOLD(clone, fold);
+    }
     Py_DECREF(tuple);
     return clone;
 }
@@ -3819,7 +3934,7 @@ time_replace(PyDateTime_Time *self, PyObject *args, PyObject *kw)
  * __getstate__ isn't exposed.
  */
 static PyObject *
-time_getstate(PyDateTime_Time *self)
+time_getstate(PyDateTime_Time *self, int proto)
 {
     PyObject *basestate;
     PyObject *result = NULL;
@@ -3827,6 +3942,9 @@ time_getstate(PyDateTime_Time *self)
     basestate =  PyBytes_FromStringAndSize((char *)self->data,
                                             _PyDateTime_TIME_DATASIZE);
     if (basestate != NULL) {
+        if (proto > 3 && TIME_GET_FOLD(self))
+            /* Set the first bit of the first byte */
+            PyBytes_AS_STRING(basestate)[0] |= (1 << 7);
         if (! HASTZINFO(self) || self->tzinfo == Py_None)
             result = PyTuple_Pack(1, basestate);
         else
@@ -3837,16 +3955,27 @@ time_getstate(PyDateTime_Time *self)
 }
 
 static PyObject *
+time_reduce_ex(PyDateTime_Time *self, PyObject *args)
+{
+    int proto;
+    if (!PyArg_ParseTuple(args, "i:__reduce_ex__", &proto))
+        return NULL;
+
+    return Py_BuildValue("(ON)", Py_TYPE(self), time_getstate(self, proto));
+}
+
+static PyObject *
 time_reduce(PyDateTime_Time *self, PyObject *arg)
 {
-    return Py_BuildValue("(ON)", Py_TYPE(self), time_getstate(self));
+    return Py_BuildValue("(ON)", Py_TYPE(self), time_getstate(self, 2));
 }
 
 static PyMethodDef time_methods[] = {
 
-    {"isoformat",   (PyCFunction)time_isoformat,        METH_NOARGS,
-     PyDoc_STR("Return string in ISO 8601 format, HH:MM:SS[.mmmmmm]"
-               "[+HH:MM].")},
+    {"isoformat",   (PyCFunction)time_isoformat,        METH_VARARGS | METH_KEYWORDS,
+     PyDoc_STR("Return string in ISO 8601 format, [HH[:MM[:SS[.mmm[uuu]]]]]"
+               "[+HH:MM].\n\n"
+               "timespec specifies what components of the time to include.\n")},
 
     {"strftime",        (PyCFunction)time_strftime,     METH_VARARGS | METH_KEYWORDS,
      PyDoc_STR("format -> strftime() style string.")},
@@ -3866,13 +3995,16 @@ static PyMethodDef time_methods[] = {
     {"replace",     (PyCFunction)time_replace,          METH_VARARGS | METH_KEYWORDS,
      PyDoc_STR("Return time with new specified fields.")},
 
+    {"__reduce_ex__", (PyCFunction)time_reduce_ex,        METH_VARARGS,
+     PyDoc_STR("__reduce_ex__(proto) -> (cls, state)")},
+
     {"__reduce__", (PyCFunction)time_reduce,        METH_NOARGS,
      PyDoc_STR("__reduce__() -> (cls, state)")},
 
     {NULL,      NULL}
 };
 
-static char time_doc[] =
+static const char time_doc[] =
 PyDoc_STR("time([hour[, minute[, second[, microsecond[, tzinfo]]]]]) --> a time object\n\
 \n\
 All arguments are optional. tzinfo may be None, or an instance of\n\
@@ -3960,12 +4092,19 @@ datetime_tzinfo(PyDateTime_DateTime *self, void *unused)
     return result;
 }
 
+static PyObject *
+datetime_fold(PyDateTime_DateTime *self, void *unused)
+{
+    return PyLong_FromLong(DATE_GET_FOLD(self));
+}
+
 static PyGetSetDef datetime_getset[] = {
     {"hour",        (getter)datetime_hour},
     {"minute",      (getter)datetime_minute},
     {"second",      (getter)datetime_second},
     {"microsecond", (getter)datetime_microsecond},
-    {"tzinfo",          (getter)datetime_tzinfo},
+    {"tzinfo",      (getter)datetime_tzinfo},
+    {"fold",        (getter)datetime_fold},
     {NULL}
 };
 
@@ -3975,7 +4114,7 @@ static PyGetSetDef datetime_getset[] = {
 
 static char *datetime_kws[] = {
     "year", "month", "day", "hour", "minute", "second",
-    "microsecond", "tzinfo", NULL
+    "microsecond", "tzinfo", "fold", NULL
 };
 
 static PyObject *
@@ -3990,6 +4129,7 @@ datetime_new(PyTypeObject *type, PyObject *args, PyObject *kw)
     int minute = 0;
     int second = 0;
     int usecond = 0;
+    int fold = 0;
     PyObject *tzinfo = Py_None;
 
     /* Check for invocation from pickle with __getstate__ state */
@@ -3997,7 +4137,7 @@ datetime_new(PyTypeObject *type, PyObject *args, PyObject *kw)
         PyTuple_GET_SIZE(args) <= 2 &&
         PyBytes_Check(state = PyTuple_GET_ITEM(args, 0)) &&
         PyBytes_GET_SIZE(state) == _PyDateTime_DATETIME_DATASIZE &&
-        MONTH_IS_SANE(PyBytes_AS_STRING(state)[2]))
+        MONTH_IS_SANE(PyBytes_AS_STRING(state)[2] & 0x7F))
     {
         PyDateTime_DateTime *me;
         char aware;
@@ -4022,28 +4162,73 @@ datetime_new(PyTypeObject *type, PyObject *args, PyObject *kw)
                 Py_INCREF(tzinfo);
                 me->tzinfo = tzinfo;
             }
+            if (pdata[2] & (1 << 7)) {
+                me->data[2] -= 128;
+                me->fold = 1;
+            }
+            else {
+                me->fold = 0;
+            }
         }
         return (PyObject *)me;
     }
 
-    if (PyArg_ParseTupleAndKeywords(args, kw, "iii|iiiiO", datetime_kws,
+    if (PyArg_ParseTupleAndKeywords(args, kw, "iii|iiiiO$i", datetime_kws,
                                     &year, &month, &day, &hour, &minute,
-                                    &second, &usecond, &tzinfo)) {
+                                    &second, &usecond, &tzinfo, &fold)) {
         if (check_date_args(year, month, day) < 0)
             return NULL;
-        if (check_time_args(hour, minute, second, usecond) < 0)
+        if (check_time_args(hour, minute, second, usecond, fold) < 0)
             return NULL;
         if (check_tzinfo_subclass(tzinfo) < 0)
             return NULL;
-        self = new_datetime_ex(year, month, day,
+        self = new_datetime_ex2(year, month, day,
                                 hour, minute, second, usecond,
-                                tzinfo, type);
+                                tzinfo, fold, type);
     }
     return self;
 }
 
-/* TM_FUNC is the shared type of localtime() and gmtime(). */
-typedef struct tm *(*TM_FUNC)(const time_t *timer);
+/* TM_FUNC is the shared type of _PyTime_localtime() and
+ * _PyTime_gmtime(). */
+typedef int (*TM_FUNC)(time_t timer, struct tm*);
+
+/* As of version 2015f max fold in IANA database is
+ * 23 hours at 1969-09-30 13:00:00 in Kwajalein. */
+static long long max_fold_seconds = 24 * 3600;
+/* NB: date(1970,1,1).toordinal() == 719163 */
+static long long epoch = 719163LL * 24 * 60 * 60;
+
+static long long
+utc_to_seconds(int year, int month, int day,
+               int hour, int minute, int second)
+{
+    long long ordinal = ymd_to_ord(year, month, day);
+    return ((ordinal * 24 + hour) * 60 + minute) * 60 + second;
+}
+
+static long long
+local(long long u)
+{
+    struct tm local_time;
+    time_t t;
+    u -= epoch;
+    t = u;
+    if (t != u) {
+        PyErr_SetString(PyExc_OverflowError,
+        "timestamp out of range for platform time_t");
+        return -1;
+    }
+    /* XXX: add bounds checking */
+    if (_PyTime_localtime(t, &local_time) != 0)
+        return -1;
+    return utc_to_seconds(local_time.tm_year + 1900,
+                          local_time.tm_mon + 1,
+                          local_time.tm_mday,
+                          local_time.tm_hour,
+                          local_time.tm_min,
+                          local_time.tm_sec);
+}
 
 /* Internal helper.
  * Build datetime from a time_t and a distinct count of microseconds.
@@ -4053,72 +4238,46 @@ static PyObject *
 datetime_from_timet_and_us(PyObject *cls, TM_FUNC f, time_t timet, int us,
                            PyObject *tzinfo)
 {
-    struct tm *tm;
+    struct tm tm;
+    int year, month, day, hour, minute, second, fold = 0;
 
-    tm = f(&timet);
-    if (tm == NULL) {
-#ifdef EINVAL
-        if (errno == 0)
-            errno = EINVAL;
-#endif
-        return PyErr_SetFromErrno(PyExc_OSError);
-    }
+    if (f(timet, &tm) != 0)
+        return NULL;
 
+    year = tm.tm_year + 1900;
+    month = tm.tm_mon + 1;
+    day = tm.tm_mday;
+    hour = tm.tm_hour;
+    minute = tm.tm_min;
     /* The platform localtime/gmtime may insert leap seconds,
-     * indicated by tm->tm_sec > 59.  We don't care about them,
+     * indicated by tm.tm_sec > 59.  We don't care about them,
      * except to the extent that passing them on to the datetime
      * constructor would raise ValueError for a reason that
      * made no sense to the user.
      */
-    if (tm->tm_sec > 59)
-        tm->tm_sec = 59;
-    return PyObject_CallFunction(cls, "iiiiiiiO",
-                                 tm->tm_year + 1900,
-                                 tm->tm_mon + 1,
-                                 tm->tm_mday,
-                                 tm->tm_hour,
-                                 tm->tm_min,
-                                 tm->tm_sec,
-                                 us,
-                                 tzinfo);
-}
-
-static time_t
-_PyTime_DoubleToTimet(double x)
-{
-    time_t result;
-    double diff;
-
-    result = (time_t)x;
-    /* How much info did we lose?  time_t may be an integral or
-     * floating type, and we don't know which.  If it's integral,
-     * we don't know whether C truncates, rounds, returns the floor,
-     * etc.  If we lost a second or more, the C rounding is
-     * unreasonable, or the input just doesn't fit in a time_t;
-     * call it an error regardless.  Note that the original cast to
-     * time_t can cause a C error too, but nothing we can do to
-     * worm around that.
-     */
-    diff = x - (double)result;
-    if (diff <= -1.0 || diff >= 1.0) {
-        PyErr_SetString(PyExc_OverflowError,
-                        "timestamp out of range for platform time_t");
-        result = (time_t)-1;
-    }
-    return result;
-}
+    second = Py_MIN(59, tm.tm_sec);
 
-/* Round a double to the nearest long.  |x| must be small enough to fit
- * in a C long; this is not checked.
- */
-static double
-_PyTime_RoundHalfEven(double x)
-{
-    double rounded = round(x);
-    if (fabs(x-rounded) == 0.5)
-        /* halfway case: round to even */
-        rounded = 2.0*round(x/2.0);
-    return rounded;
+    if (tzinfo == Py_None && f == _PyTime_localtime) {
+        long long probe_seconds, result_seconds, transition;
+
+        result_seconds = utc_to_seconds(year, month, day,
+                                        hour, minute, second);
+        /* Probe max_fold_seconds to detect a fold. */
+        probe_seconds = local(epoch + timet - max_fold_seconds);
+        if (probe_seconds == -1)
+            return NULL;
+        transition = result_seconds - probe_seconds - max_fold_seconds;
+        if (transition < 0) {
+            probe_seconds = local(epoch + timet + transition);
+            if (probe_seconds == -1)
+                return NULL;
+            if (probe_seconds == result_seconds)
+                fold = 1;
+        }
+    }
+    return new_datetime_ex2(year, month, day, hour,
+                            minute, second, us, tzinfo, fold,
+                            (PyTypeObject *)cls);
 }
 
 /* Internal helper.
@@ -4129,32 +4288,17 @@ _PyTime_RoundHalfEven(double x)
  * to get that much precision (e.g., C time() isn't good enough).
  */
 static PyObject *
-datetime_from_timestamp(PyObject *cls, TM_FUNC f, double timestamp,
+datetime_from_timestamp(PyObject *cls, TM_FUNC f, PyObject *timestamp,
                         PyObject *tzinfo)
 {
     time_t timet;
-    double fraction;
-    int us;
+    long us;
 
-    timet = _PyTime_DoubleToTimet(timestamp);
-    if (timet == (time_t)-1 && PyErr_Occurred())
+    if (_PyTime_ObjectToTimeval(timestamp,
+                                &timet, &us, _PyTime_ROUND_HALF_EVEN) == -1)
         return NULL;
-    fraction = timestamp - (double)timet;
-    us = (int)_PyTime_RoundHalfEven(fraction * 1e6);
-    if (us < 0) {
-        /* Truncation towards zero is not what we wanted
-           for negative numbers (Python's mod semantics) */
-        timet -= 1;
-        us += 1000000;
-    }
-    /* If timestamp is less than one microsecond smaller than a
-     * full second, round up. Otherwise, ValueErrors are raised
-     * for some floats. */
-    if (us == 1000000) {
-        timet += 1;
-        us = 0;
-    }
-    return datetime_from_timet_and_us(cls, f, timet, us, tzinfo);
+
+    return datetime_from_timet_and_us(cls, f, timet, (int)us, tzinfo);
 }
 
 /* Internal helper.
@@ -4201,14 +4345,12 @@ datetime_datetime_now_impl(PyTypeObject *type, PyObject *tz)
         return NULL;
 
     self = datetime_best_possible((PyObject *)type,
-                                  tz == Py_None ? localtime : gmtime,
+                                  tz == Py_None ? _PyTime_localtime :
+                                  _PyTime_gmtime,
                                   tz);
     if (self != NULL && tz != Py_None) {
         /* Convert UTC to tzinfo's zone. */
-        PyObject *temp = self;
-
-        self = _PyObject_CallMethodId(tz, &PyId_fromutc, "O", self);
-        Py_DECREF(temp);
+        self = _PyObject_CallMethodId(tz, &PyId_fromutc, "N", self);
     }
     return self;
 }
@@ -4219,7 +4361,7 @@ datetime_datetime_now_impl(PyTypeObject *type, PyObject *tz)
 static PyObject *
 datetime_utcnow(PyObject *cls, PyObject *dummy)
 {
-    return datetime_best_possible(cls, gmtime, Py_None);
+    return datetime_best_possible(cls, _PyTime_gmtime, Py_None);
 }
 
 /* Return new local datetime from timestamp (Python timestamp -- a double). */
@@ -4227,26 +4369,24 @@ static PyObject *
 datetime_fromtimestamp(PyObject *cls, PyObject *args, PyObject *kw)
 {
     PyObject *self;
-    double timestamp;
+    PyObject *timestamp;
     PyObject *tzinfo = Py_None;
     static char *keywords[] = {"timestamp", "tz", NULL};
 
-    if (! PyArg_ParseTupleAndKeywords(args, kw, "d|O:fromtimestamp",
+    if (! PyArg_ParseTupleAndKeywords(args, kw, "O|O:fromtimestamp",
                                       keywords, &timestamp, &tzinfo))
         return NULL;
     if (check_tzinfo_subclass(tzinfo) < 0)
         return NULL;
 
     self = datetime_from_timestamp(cls,
-                                   tzinfo == Py_None ? localtime : gmtime,
+                                   tzinfo == Py_None ? _PyTime_localtime :
+                                   _PyTime_gmtime,
                                    timestamp,
                                    tzinfo);
     if (self != NULL && tzinfo != Py_None) {
         /* Convert UTC to tzinfo's zone. */
-        PyObject *temp = self;
-
-        self = _PyObject_CallMethodId(tzinfo, &PyId_fromutc, "O", self);
-        Py_DECREF(temp);
+        self = _PyObject_CallMethodId(tzinfo, &PyId_fromutc, "N", self);
     }
     return self;
 }
@@ -4255,11 +4395,11 @@ datetime_fromtimestamp(PyObject *cls, PyObject *args, PyObject *kw)
 static PyObject *
 datetime_utcfromtimestamp(PyObject *cls, PyObject *args)
 {
-    double timestamp;
+    PyObject *timestamp;
     PyObject *result = NULL;
 
-    if (PyArg_ParseTuple(args, "d:utcfromtimestamp", &timestamp))
-        result = datetime_from_timestamp(cls, gmtime, timestamp,
+    if (PyArg_ParseTuple(args, "O:utcfromtimestamp", &timestamp))
+        result = datetime_from_timestamp(cls, _PyTime_gmtime, timestamp,
                                          Py_None);
     return result;
 }
@@ -4288,27 +4428,32 @@ datetime_strptime(PyObject *cls, PyObject *args)
 static PyObject *
 datetime_combine(PyObject *cls, PyObject *args, PyObject *kw)
 {
-    static char *keywords[] = {"date", "time", NULL};
+    static char *keywords[] = {"date", "time", "tzinfo", NULL};
     PyObject *date;
     PyObject *time;
+    PyObject *tzinfo = NULL;
     PyObject *result = NULL;
 
-    if (PyArg_ParseTupleAndKeywords(args, kw, "O!O!:combine", keywords,
+    if (PyArg_ParseTupleAndKeywords(args, kw, "O!O!|O:combine", keywords,
                                     &PyDateTime_DateType, &date,
-                                    &PyDateTime_TimeType, &time)) {
-        PyObject *tzinfo = Py_None;
-
-        if (HASTZINFO(time))
-            tzinfo = ((PyDateTime_Time *)time)->tzinfo;
+                                    &PyDateTime_TimeType, &time, &tzinfo)) {
+        if (tzinfo == NULL) {
+            if (HASTZINFO(time))
+                tzinfo = ((PyDateTime_Time *)time)->tzinfo;
+            else
+                tzinfo = Py_None;
+        }
         result = PyObject_CallFunction(cls, "iiiiiiiO",
-                                        GET_YEAR(date),
-                                        GET_MONTH(date),
-                                        GET_DAY(date),
-                                        TIME_GET_HOUR(time),
-                                        TIME_GET_MINUTE(time),
-                                        TIME_GET_SECOND(time),
-                                        TIME_GET_MICROSECOND(time),
-                                        tzinfo);
+                                       GET_YEAR(date),
+                                       GET_MONTH(date),
+                                       GET_DAY(date),
+                                       TIME_GET_HOUR(time),
+                                       TIME_GET_MINUTE(time),
+                                       TIME_GET_SECOND(time),
+                                       TIME_GET_MICROSECOND(time),
+                                       tzinfo);
+        if (result)
+            DATE_SET_FOLD(result, TIME_GET_FOLD(time));
     }
     return result;
 }
@@ -4376,7 +4521,7 @@ add_datetime_timedelta(PyDateTime_DateTime *date, PyDateTime_Delta *delta,
     else
         return new_datetime(year, month, day,
                             hour, minute, second, microsecond,
-                            HASTZINFO(date) ? date->tzinfo : Py_None);
+                            HASTZINFO(date) ? date->tzinfo : Py_None, 0);
 }
 
 static PyObject *
@@ -4469,9 +4614,7 @@ datetime_subtract(PyObject *left, PyObject *right)
                 return NULL;
 
             if (offdiff != NULL) {
-                PyObject *temp = result;
-                result = delta_subtract(result, offdiff);
-                Py_DECREF(temp);
+                Py_SETREF(result, delta_subtract(result, offdiff));
                 Py_DECREF(offdiff);
             }
         }
@@ -4521,6 +4664,8 @@ datetime_repr(PyDateTime_DateTime *self)
                       GET_YEAR(self), GET_MONTH(self), GET_DAY(self),
                       DATE_GET_HOUR(self), DATE_GET_MINUTE(self));
     }
+    if (baserepr != NULL && DATE_GET_FOLD(self) != 0)
+        baserepr = append_keyword_fold(baserepr, DATE_GET_FOLD(self));
     if (baserepr == NULL || ! HASTZINFO(self))
         return baserepr;
     return append_keyword_tzinfo(baserepr, self->tzinfo);
@@ -4536,25 +4681,55 @@ static PyObject *
 datetime_isoformat(PyDateTime_DateTime *self, PyObject *args, PyObject *kw)
 {
     int sep = 'T';
-    static char *keywords[] = {"sep", NULL};
+    char *timespec = NULL;
+    static char *keywords[] = {"sep", "timespec", NULL};
     char buffer[100];
-    PyObject *result;
+    PyObject *result = NULL;
     int us = DATE_GET_MICROSECOND(self);
+    static char *specs[][2] = {
+        {"hours", "%04d-%02d-%02d%c%02d"},
+        {"minutes", "%04d-%02d-%02d%c%02d:%02d"},
+        {"seconds", "%04d-%02d-%02d%c%02d:%02d:%02d"},
+        {"milliseconds", "%04d-%02d-%02d%c%02d:%02d:%02d.%03d"},
+        {"microseconds", "%04d-%02d-%02d%c%02d:%02d:%02d.%06d"},
+    };
+    size_t given_spec;
 
-    if (!PyArg_ParseTupleAndKeywords(args, kw, "|C:isoformat", keywords, &sep))
+    if (!PyArg_ParseTupleAndKeywords(args, kw, "|Cs:isoformat", keywords, &sep, &timespec))
         return NULL;
-    if (us)
-        result = PyUnicode_FromFormat("%04d-%02d-%02d%c%02d:%02d:%02d.%06d",
+
+    if (timespec == NULL || strcmp(timespec, "auto") == 0) {
+        if (us == 0) {
+            /* seconds */
+            given_spec = 2;
+        }
+        else {
+            /* microseconds */
+            given_spec = 4;
+        }
+    }
+    else {
+        for (given_spec = 0; given_spec < Py_ARRAY_LENGTH(specs); given_spec++) {
+            if (strcmp(timespec, specs[given_spec][0]) == 0) {
+                if (given_spec == 3) {
+                    us = us / 1000;
+                }
+                break;
+            }
+        }
+    }
+
+    if (given_spec == Py_ARRAY_LENGTH(specs)) {
+        PyErr_Format(PyExc_ValueError, "Unknown timespec value");
+        return NULL;
+    }
+    else {
+        result = PyUnicode_FromFormat(specs[given_spec][1],
                                       GET_YEAR(self), GET_MONTH(self),
                                       GET_DAY(self), (int)sep,
                                       DATE_GET_HOUR(self), DATE_GET_MINUTE(self),
                                       DATE_GET_SECOND(self), us);
-    else
-        result = PyUnicode_FromFormat("%04d-%02d-%02d%c%02d:%02d:%02d",
-                                      GET_YEAR(self), GET_MONTH(self),
-                                      GET_DAY(self), (int)sep,
-                                      DATE_GET_HOUR(self), DATE_GET_MINUTE(self),
-                                      DATE_GET_SECOND(self));
+    }
 
     if (!result || !HASTZINFO(self))
         return result;
@@ -4581,6 +4756,70 @@ datetime_ctime(PyDateTime_DateTime *self)
 /* Miscellaneous methods. */
 
 static PyObject *
+flip_fold(PyObject *dt)
+{
+    return new_datetime_ex2(GET_YEAR(dt),
+                            GET_MONTH(dt),
+                            GET_DAY(dt),
+                            DATE_GET_HOUR(dt),
+                            DATE_GET_MINUTE(dt),
+                            DATE_GET_SECOND(dt),
+                            DATE_GET_MICROSECOND(dt),
+                            HASTZINFO(dt) ?
+                             ((PyDateTime_DateTime *)dt)->tzinfo : Py_None,
+                            !DATE_GET_FOLD(dt),
+                            Py_TYPE(dt));
+}
+
+static PyObject *
+get_flip_fold_offset(PyObject *dt)
+{
+    PyObject *result, *flip_dt;
+
+    flip_dt = flip_fold(dt);
+    if (flip_dt == NULL)
+        return NULL;
+    result = datetime_utcoffset(flip_dt, NULL);
+    Py_DECREF(flip_dt);
+    return result;
+}
+
+/* PEP 495 exception: Whenever one or both of the operands in
+ * inter-zone comparison is such that its utcoffset() depends
+ * on the value of its fold fold attribute, the result is False.
+ *
+ * Return 1 if exception applies, 0 if not,  and -1 on error.
+ */
+static int
+pep495_eq_exception(PyObject *self, PyObject *other,
+                    PyObject *offset_self, PyObject *offset_other)
+{
+    int result = 0;
+    PyObject *flip_offset;
+
+    flip_offset = get_flip_fold_offset(self);
+    if (flip_offset == NULL)
+        return -1;
+    if (flip_offset != offset_self &&
+        delta_cmp(flip_offset, offset_self))
+    {
+        result = 1;
+        goto done;
+    }
+    Py_DECREF(flip_offset);
+
+    flip_offset = get_flip_fold_offset(other);
+    if (flip_offset == NULL)
+        return -1;
+    if (flip_offset != offset_other &&
+        delta_cmp(flip_offset, offset_other))
+        result = 1;
+ done:
+    Py_DECREF(flip_offset);
+    return result;
+}
+
+static PyObject *
 datetime_richcompare(PyObject *self, PyObject *other, int op)
 {
     PyObject *result = NULL;
@@ -4627,6 +4866,13 @@ datetime_richcompare(PyObject *self, PyObject *other, int op)
         diff = memcmp(((PyDateTime_DateTime *)self)->data,
                       ((PyDateTime_DateTime *)other)->data,
                       _PyDateTime_DATETIME_DATASIZE);
+        if ((op == Py_EQ || op == Py_NE) && diff == 0) {
+            int ex = pep495_eq_exception(self, other, offset1, offset2);
+            if (ex == -1)
+                goto done;
+            if (ex)
+                diff = 1;
+        }
         result = diff_to_bool(diff, op);
     }
     else if (offset1 != Py_None && offset2 != Py_None) {
@@ -4642,6 +4888,13 @@ datetime_richcompare(PyObject *self, PyObject *other, int op)
             diff = GET_TD_SECONDS(delta) |
                    GET_TD_MICROSECONDS(delta);
         Py_DECREF(delta);
+        if ((op == Py_EQ || op == Py_NE) && diff == 0) {
+            int ex = pep495_eq_exception(self, other, offset1, offset2);
+            if (ex == -1)
+                goto done;
+            if (ex)
+                diff = 1;
+        }
         result = diff_to_bool(diff, op);
     }
     else if (op == Py_EQ) {
@@ -4667,9 +4920,26 @@ static Py_hash_t
 datetime_hash(PyDateTime_DateTime *self)
 {
     if (self->hashcode == -1) {
-        PyObject *offset;
-
-        offset = datetime_utcoffset((PyObject *)self, NULL);
+        PyObject *offset, *self0;
+        if (DATE_GET_FOLD(self)) {
+            self0 = new_datetime_ex2(GET_YEAR(self),
+                                     GET_MONTH(self),
+                                     GET_DAY(self),
+                                     DATE_GET_HOUR(self),
+                                     DATE_GET_MINUTE(self),
+                                     DATE_GET_SECOND(self),
+                                     DATE_GET_MICROSECOND(self),
+                                     HASTZINFO(self) ? self->tzinfo : Py_None,
+                                     0, Py_TYPE(self));
+            if (self0 == NULL)
+                return -1;
+        }
+        else {
+            self0 = (PyObject *)self;
+            Py_INCREF(self0);
+        }
+        offset = datetime_utcoffset(self0, NULL);
+        Py_DECREF(self0);
 
         if (offset == NULL)
             return -1;
@@ -4723,76 +4993,80 @@ datetime_replace(PyDateTime_DateTime *self, PyObject *args, PyObject *kw)
     int ss = DATE_GET_SECOND(self);
     int us = DATE_GET_MICROSECOND(self);
     PyObject *tzinfo = HASTZINFO(self) ? self->tzinfo : Py_None;
+    int fold = DATE_GET_FOLD(self);
 
-    if (! PyArg_ParseTupleAndKeywords(args, kw, "|iiiiiiiO:replace",
+    if (! PyArg_ParseTupleAndKeywords(args, kw, "|iiiiiiiO$i:replace",
                                       datetime_kws,
                                       &y, &m, &d, &hh, &mm, &ss, &us,
-                                      &tzinfo))
+                                      &tzinfo, &fold))
         return NULL;
     tuple = Py_BuildValue("iiiiiiiO", y, m, d, hh, mm, ss, us, tzinfo);
     if (tuple == NULL)
         return NULL;
     clone = datetime_new(Py_TYPE(self), tuple, NULL);
+
+    if (clone != NULL) {
+        if (fold != 0 && fold != 1) {
+            PyErr_SetString(PyExc_ValueError,
+                            "fold must be either 0 or 1");
+            return NULL;
+        }
+        DATE_SET_FOLD(clone, fold);
+    }
     Py_DECREF(tuple);
     return clone;
 }
 
 static PyObject *
-local_timezone(PyDateTime_DateTime *utc_time)
+local_timezone_from_timestamp(time_t timestamp)
 {
     PyObject *result = NULL;
-    struct tm *timep;
-    time_t timestamp;
     PyObject *delta;
-    PyObject *one_second;
-    PyObject *seconds;
+    struct tm local_time_tm;
     PyObject *nameo = NULL;
     const char *zone = NULL;
 
-    delta = new_delta(ymd_to_ord(GET_YEAR(utc_time), GET_MONTH(utc_time),
-                                 GET_DAY(utc_time)) - 719163,
-                      60 * (60 * DATE_GET_HOUR(utc_time) +
-                            DATE_GET_MINUTE(utc_time)) +
-                      DATE_GET_SECOND(utc_time),
-                      0, 0);
-    if (delta == NULL)
+    if (_PyTime_localtime(timestamp, &local_time_tm) != 0)
         return NULL;
-    one_second = new_delta(0, 1, 0, 0);
-    if (one_second == NULL)
-        goto error;
-    seconds = divide_timedelta_timedelta((PyDateTime_Delta *)delta,
-                                         (PyDateTime_Delta *)one_second);
-    Py_DECREF(one_second);
-    if (seconds == NULL)
-        goto error;
-    Py_DECREF(delta);
-    timestamp = PyLong_AsLong(seconds);
-    Py_DECREF(seconds);
-    if (timestamp == -1 && PyErr_Occurred())
-        return NULL;
-    timep = localtime(&timestamp);
 #ifdef HAVE_STRUCT_TM_TM_ZONE
-    zone = timep->tm_zone;
-    delta = new_delta(0, timep->tm_gmtoff, 0, 1);
+    zone = local_time_tm.tm_zone;
+    delta = new_delta(0, local_time_tm.tm_gmtoff, 0, 1);
 #else /* HAVE_STRUCT_TM_TM_ZONE */
     {
-        PyObject *local_time;
-        local_time = new_datetime(timep->tm_year + 1900, timep->tm_mon + 1,
-                                  timep->tm_mday, timep->tm_hour, timep->tm_min,
-                                  timep->tm_sec, DATE_GET_MICROSECOND(utc_time),
-                                  utc_time->tzinfo);
-        if (local_time == NULL)
-            goto error;
-        delta = datetime_subtract(local_time, (PyObject*)utc_time);
-        /* XXX: before relying on tzname, we should compare delta
-           to the offset implied by timezone/altzone */
-        if (daylight && timep->tm_isdst >= 0)
-            zone = tzname[timep->tm_isdst % 2];
-        else
-            zone = tzname[0];
+        PyObject *local_time, *utc_time;
+        struct tm utc_time_tm;
+        char buf[100];
+        strftime(buf, sizeof(buf), "%Z", &local_time_tm);
+        zone = buf;
+        local_time = new_datetime(local_time_tm.tm_year + 1900,
+                                  local_time_tm.tm_mon + 1,
+                                  local_time_tm.tm_mday,
+                                  local_time_tm.tm_hour,
+                                  local_time_tm.tm_min,
+                                  local_time_tm.tm_sec, 0, Py_None, 0);
+        if (local_time == NULL) {
+            return NULL;
+        }
+        if (_PyTime_gmtime(timestamp, &utc_time_tm) != 0)
+            return NULL;
+        utc_time = new_datetime(utc_time_tm.tm_year + 1900,
+                                utc_time_tm.tm_mon + 1,
+                                utc_time_tm.tm_mday,
+                                utc_time_tm.tm_hour,
+                                utc_time_tm.tm_min,
+                                utc_time_tm.tm_sec, 0, Py_None, 0);
+        if (utc_time == NULL) {
+            Py_DECREF(local_time);
+            return NULL;
+        }
+        delta = datetime_subtract(local_time, utc_time);
         Py_DECREF(local_time);
+        Py_DECREF(utc_time);
     }
 #endif /* HAVE_STRUCT_TM_TM_ZONE */
+    if (delta == NULL) {
+            return NULL;
+    }
     if (zone != NULL) {
         nameo = PyUnicode_DecodeLocale(zone, "surrogateescape");
         if (nameo == NULL)
@@ -4805,12 +5079,65 @@ local_timezone(PyDateTime_DateTime *utc_time)
     return result;
 }
 
+static PyObject *
+local_timezone(PyDateTime_DateTime *utc_time)
+{
+    time_t timestamp;
+    PyObject *delta;
+    PyObject *one_second;
+    PyObject *seconds;
+
+    delta = datetime_subtract((PyObject *)utc_time, PyDateTime_Epoch);
+    if (delta == NULL)
+        return NULL;
+    one_second = new_delta(0, 1, 0, 0);
+    if (one_second == NULL) {
+        Py_DECREF(delta);
+        return NULL;
+    }
+    seconds = divide_timedelta_timedelta((PyDateTime_Delta *)delta,
+                                         (PyDateTime_Delta *)one_second);
+    Py_DECREF(one_second);
+    Py_DECREF(delta);
+    if (seconds == NULL)
+        return NULL;
+    timestamp = _PyLong_AsTime_t(seconds);
+    Py_DECREF(seconds);
+    if (timestamp == -1 && PyErr_Occurred())
+        return NULL;
+    return local_timezone_from_timestamp(timestamp);
+}
+
+static long long
+local_to_seconds(int year, int month, int day,
+                 int hour, int minute, int second, int fold);
+
+static PyObject *
+local_timezone_from_local(PyDateTime_DateTime *local_dt)
+{
+    long long seconds;
+    time_t timestamp;
+    seconds = local_to_seconds(GET_YEAR(local_dt),
+                               GET_MONTH(local_dt),
+                               GET_DAY(local_dt),
+                               DATE_GET_HOUR(local_dt),
+                               DATE_GET_MINUTE(local_dt),
+                               DATE_GET_SECOND(local_dt),
+                               DATE_GET_FOLD(local_dt));
+    if (seconds == -1)
+        return NULL;
+    /* XXX: add bounds check */
+    timestamp = seconds - epoch;
+    return local_timezone_from_timestamp(timestamp);
+}
+
 static PyDateTime_DateTime *
 datetime_astimezone(PyDateTime_DateTime *self, PyObject *args, PyObject *kw)
 {
     PyDateTime_DateTime *result;
     PyObject *offset;
     PyObject *temp;
+    PyObject *self_tzinfo;
     PyObject *tzinfo = Py_None;
     static char *keywords[] = {"tz", NULL};
 
@@ -4821,27 +5148,27 @@ datetime_astimezone(PyDateTime_DateTime *self, PyObject *args, PyObject *kw)
     if (check_tzinfo_subclass(tzinfo) == -1)
         return NULL;
 
-    if (!HASTZINFO(self) || self->tzinfo == Py_None)
-        goto NeedAware;
+    if (!HASTZINFO(self) || self->tzinfo == Py_None) {
+        self_tzinfo = local_timezone_from_local(self);
+        if (self_tzinfo == NULL)
+            return NULL;
+    } else {
+        self_tzinfo = self->tzinfo;
+        Py_INCREF(self_tzinfo);
+    }
 
     /* Conversion to self's own time zone is a NOP. */
-    if (self->tzinfo == tzinfo) {
+    if (self_tzinfo == tzinfo) {
+        Py_DECREF(self_tzinfo);
         Py_INCREF(self);
         return self;
     }
 
     /* Convert self to UTC. */
-    offset = datetime_utcoffset((PyObject *)self, NULL);
+    offset = call_utcoffset(self_tzinfo, (PyObject *)self);
+    Py_DECREF(self_tzinfo);
     if (offset == NULL)
         return NULL;
-    if (offset == Py_None) {
-        Py_DECREF(offset);
-      NeedAware:
-        PyErr_SetString(PyExc_ValueError, "astimezone() cannot be applied to "
-                        "a naive datetime");
-        return NULL;
-    }
-
     /* result = self - offset */
     result = (PyDateTime_DateTime *)add_datetime_timedelta(self,
                                        (PyDateTime_Delta *)offset, -1);
@@ -4849,6 +5176,32 @@ datetime_astimezone(PyDateTime_DateTime *self, PyObject *args, PyObject *kw)
     if (result == NULL)
         return NULL;
 
+    /* Make sure result is aware and UTC. */
+    if (!HASTZINFO(result)) {
+        temp = (PyObject *)result;
+        result = (PyDateTime_DateTime *)
+                   new_datetime_ex2(GET_YEAR(result),
+                                    GET_MONTH(result),
+                                    GET_DAY(result),
+                                    DATE_GET_HOUR(result),
+                                    DATE_GET_MINUTE(result),
+                                    DATE_GET_SECOND(result),
+                                    DATE_GET_MICROSECOND(result),
+                                    PyDateTime_TimeZone_UTC,
+                                    DATE_GET_FOLD(result),
+                                    Py_TYPE(result));
+        Py_DECREF(temp);
+        if (result == NULL)
+            return NULL;
+    }
+    else {
+        /* Result is already aware - just replace tzinfo. */
+        temp = result->tzinfo;
+        result->tzinfo = PyDateTime_TimeZone_UTC;
+        Py_INCREF(result->tzinfo);
+        Py_DECREF(temp);
+    }
+
     /* Attach new tzinfo and let fromutc() do the rest. */
     temp = result->tzinfo;
     if (tzinfo == Py_None) {
@@ -4896,6 +5249,56 @@ datetime_timetuple(PyDateTime_DateTime *self)
                              dstflag);
 }
 
+static long long
+local_to_seconds(int year, int month, int day,
+                 int hour, int minute, int second, int fold)
+{
+    long long t, a, b, u1, u2, t1, t2, lt;
+    t = utc_to_seconds(year, month, day, hour, minute, second);
+    /* Our goal is to solve t = local(u) for u. */
+    lt = local(t);
+    if (lt == -1)
+        return -1;
+    a = lt - t;
+    u1 = t - a;
+    t1 = local(u1);
+    if (t1 == -1)
+        return -1;
+    if (t1 == t) {
+        /* We found one solution, but it may not be the one we need.
+         * Look for an earlier solution (if `fold` is 0), or a
+         * later one (if `fold` is 1). */
+        if (fold)
+            u2 = u1 + max_fold_seconds;
+        else
+            u2 = u1 - max_fold_seconds;
+        lt = local(u2);
+        if (lt == -1)
+            return -1;
+        b = lt - u2;
+        if (a == b)
+            return u1;
+    }
+    else {
+        b = t1 - u1;
+        assert(a != b);
+    }
+    u2 = t - b;
+    t2 = local(u2);
+    if (t2 == -1)
+        return -1;
+    if (t2 == t)
+        return u2;
+    if (t1 == t)
+        return u1;
+    /* We have found both offsets a and b, but neither t - a nor t - b is
+     * a solution.  This means t is in the gap. */
+    return fold?Py_MIN(u1, u2):Py_MAX(u1, u2);
+}
+
+/* date(1970,1,1).toordinal() == 719163 */
+#define EPOCH_SECONDS (719163LL * 24 * 60 * 60)
+
 static PyObject *
 datetime_timestamp(PyDateTime_DateTime *self)
 {
@@ -4910,33 +5313,18 @@ datetime_timestamp(PyDateTime_DateTime *self)
         Py_DECREF(delta);
     }
     else {
-        struct tm time;
-        time_t timestamp;
-        memset((void *) &time, '\0', sizeof(struct tm));
-        time.tm_year = GET_YEAR(self) - 1900;
-        time.tm_mon = GET_MONTH(self) - 1;
-        time.tm_mday = GET_DAY(self);
-        time.tm_hour = DATE_GET_HOUR(self);
-        time.tm_min = DATE_GET_MINUTE(self);
-        time.tm_sec = DATE_GET_SECOND(self);
-        time.tm_wday = -1;
-        time.tm_isdst = -1;
-        timestamp = mktime(&time);
-        if (timestamp == (time_t)(-1)
-#ifndef _AIX
-            /* Return value of -1 does not necessarily mean an error,
-             * but tm_wday cannot remain set to -1 if mktime succeeded. */
-            && time.tm_wday == -1
-#else
-            /* on AIX, tm_wday is always sets, even on error */
-#endif
-          )
-        {
-            PyErr_SetString(PyExc_OverflowError,
-                            "timestamp out of range");
+        long long seconds;
+        seconds = local_to_seconds(GET_YEAR(self),
+                                   GET_MONTH(self),
+                                   GET_DAY(self),
+                                   DATE_GET_HOUR(self),
+                                   DATE_GET_MINUTE(self),
+                                   DATE_GET_SECOND(self),
+                                   DATE_GET_FOLD(self));
+        if (seconds == -1)
             return NULL;
-        }
-        result = PyFloat_FromDouble(timestamp + DATE_GET_MICROSECOND(self) / 1e6);
+        result = PyFloat_FromDouble(seconds - EPOCH_SECONDS +
+                                    DATE_GET_MICROSECOND(self) / 1e6);
     }
     return result;
 }
@@ -4956,7 +5344,8 @@ datetime_gettime(PyDateTime_DateTime *self)
                     DATE_GET_MINUTE(self),
                     DATE_GET_SECOND(self),
                     DATE_GET_MICROSECOND(self),
-                    Py_None);
+                    Py_None,
+                    DATE_GET_FOLD(self));
 }
 
 static PyObject *
@@ -4966,7 +5355,8 @@ datetime_gettimetz(PyDateTime_DateTime *self)
                     DATE_GET_MINUTE(self),
                     DATE_GET_SECOND(self),
                     DATE_GET_MICROSECOND(self),
-                    GET_DT_TZINFO(self));
+                    GET_DT_TZINFO(self),
+                    DATE_GET_FOLD(self));
 }
 
 static PyObject *
@@ -5018,7 +5408,7 @@ datetime_utctimetuple(PyDateTime_DateTime *self)
  * __getstate__ isn't exposed.
  */
 static PyObject *
-datetime_getstate(PyDateTime_DateTime *self)
+datetime_getstate(PyDateTime_DateTime *self, int proto)
 {
     PyObject *basestate;
     PyObject *result = NULL;
@@ -5026,6 +5416,9 @@ datetime_getstate(PyDateTime_DateTime *self)
     basestate = PyBytes_FromStringAndSize((char *)self->data,
                                            _PyDateTime_DATETIME_DATASIZE);
     if (basestate != NULL) {
+        if (proto > 3 && DATE_GET_FOLD(self))
+            /* Set the first bit of the third byte */
+            PyBytes_AS_STRING(basestate)[2] |= (1 << 7);
         if (! HASTZINFO(self) || self->tzinfo == Py_None)
             result = PyTuple_Pack(1, basestate);
         else
@@ -5036,9 +5429,19 @@ datetime_getstate(PyDateTime_DateTime *self)
 }
 
 static PyObject *
+datetime_reduce_ex(PyDateTime_DateTime *self, PyObject *args)
+{
+    int proto;
+    if (!PyArg_ParseTuple(args, "i:__reduce_ex__", &proto))
+        return NULL;
+
+    return Py_BuildValue("(ON)", Py_TYPE(self), datetime_getstate(self, proto));
+}
+
+static PyObject *
 datetime_reduce(PyDateTime_DateTime *self, PyObject *arg)
 {
-    return Py_BuildValue("(ON)", Py_TYPE(self), datetime_getstate(self));
+    return Py_BuildValue("(ON)", Py_TYPE(self), datetime_getstate(self, 2));
 }
 
 static PyMethodDef datetime_methods[] = {
@@ -5093,9 +5496,12 @@ static PyMethodDef datetime_methods[] = {
 
     {"isoformat",   (PyCFunction)datetime_isoformat, METH_VARARGS | METH_KEYWORDS,
      PyDoc_STR("[sep] -> string in ISO 8601 format, "
-               "YYYY-MM-DDTHH:MM:SS[.mmmmmm][+HH:MM].\n\n"
+               "YYYY-MM-DDT[HH[:MM[:SS[.mmm[uuu]]]]][+HH:MM].\n"
                "sep is used to separate the year from the time, and "
-               "defaults to 'T'.")},
+               "defaults to 'T'.\n"
+               "timespec specifies what components of the time to include"
+               " (allowed values are 'auto', 'hours', 'minutes', 'seconds',"
+               " 'milliseconds', and 'microseconds').\n")},
 
     {"utcoffset",       (PyCFunction)datetime_utcoffset, METH_NOARGS,
      PyDoc_STR("Return self.tzinfo.utcoffset(self).")},
@@ -5112,13 +5518,16 @@ static PyMethodDef datetime_methods[] = {
     {"astimezone",  (PyCFunction)datetime_astimezone, METH_VARARGS | METH_KEYWORDS,
      PyDoc_STR("tz -> convert to local time in new timezone tz\n")},
 
+    {"__reduce_ex__", (PyCFunction)datetime_reduce_ex,     METH_VARARGS,
+     PyDoc_STR("__reduce_ex__(proto) -> (cls, state)")},
+
     {"__reduce__", (PyCFunction)datetime_reduce,     METH_NOARGS,
      PyDoc_STR("__reduce__() -> (cls, state)")},
 
     {NULL,      NULL}
 };
 
-static char datetime_doc[] =
+static const char datetime_doc[] =
 PyDoc_STR("datetime(year, month, day[, hour[, minute[, second[, microsecond[,tzinfo]]]]])\n\
 \n\
 The year, month and day arguments are required. tzinfo may be None, or an\n\
@@ -5201,7 +5610,9 @@ static PyDateTime_CAPI CAPI = {
     new_time_ex,
     new_delta_ex,
     datetime_fromtimestamp,
-    date_fromtimestamp
+    date_fromtimestamp,
+    new_datetime_ex2,
+    new_time_ex2
 };
 
 
@@ -5282,12 +5693,12 @@ PyInit__datetime(void)
     /* time values */
     d = PyDateTime_TimeType.tp_dict;
 
-    x = new_time(0, 0, 0, 0, Py_None);
+    x = new_time(0, 0, 0, 0, Py_None, 0);
     if (x == NULL || PyDict_SetItemString(d, "min", x) < 0)
         return NULL;
     Py_DECREF(x);
 
-    x = new_time(23, 59, 59, 999999, Py_None);
+    x = new_time(23, 59, 59, 999999, Py_None, 0);
     if (x == NULL || PyDict_SetItemString(d, "max", x) < 0)
         return NULL;
     Py_DECREF(x);
@@ -5300,12 +5711,12 @@ PyInit__datetime(void)
     /* datetime values */
     d = PyDateTime_DateTimeType.tp_dict;
 
-    x = new_datetime(1, 1, 1, 0, 0, 0, 0, Py_None);
+    x = new_datetime(1, 1, 1, 0, 0, 0, 0, Py_None, 0);
     if (x == NULL || PyDict_SetItemString(d, "min", x) < 0)
         return NULL;
     Py_DECREF(x);
 
-    x = new_datetime(MAXYEAR, 12, 31, 23, 59, 59, 999999, Py_None);
+    x = new_datetime(MAXYEAR, 12, 31, 23, 59, 59, 999999, Py_None, 0);
     if (x == NULL || PyDict_SetItemString(d, "max", x) < 0)
         return NULL;
     Py_DECREF(x);
@@ -5347,7 +5758,7 @@ PyInit__datetime(void)
 
     /* Epoch */
     PyDateTime_Epoch = new_datetime(1970, 1, 1, 0, 0, 0, 0,
-                                    PyDateTime_TimeZone_UTC);
+                                    PyDateTime_TimeZone_UTC, 0);
     if (PyDateTime_Epoch == NULL)
       return NULL;
 
@@ -5382,19 +5793,19 @@ PyInit__datetime(void)
     /* A 4-year cycle has an extra leap day over what we'd get from
      * pasting together 4 single years.
      */
-    assert(DI4Y == 4 * 365 + 1);
+    Py_BUILD_ASSERT(DI4Y == 4 * 365 + 1);
     assert(DI4Y == days_before_year(4+1));
 
     /* Similarly, a 400-year cycle has an extra leap day over what we'd
      * get from pasting together 4 100-year cycles.
      */
-    assert(DI400Y == 4 * DI100Y + 1);
+    Py_BUILD_ASSERT(DI400Y == 4 * DI100Y + 1);
     assert(DI400Y == days_before_year(400+1));
 
     /* OTOH, a 100-year cycle has one fewer leap day than we'd get from
      * pasting together 25 4-year cycles.
      */
-    assert(DI100Y == 25 * DI4Y - 1);
+    Py_BUILD_ASSERT(DI100Y == 25 * DI4Y - 1);
     assert(DI100Y == days_before_year(100+1));
 
     one = PyLong_FromLong(1);