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| author | Jay Belanger <jay.p.belanger@gmail.com> | 2012-11-18 23:03:08 -0600 |
|---|---|---|
| committer | Jay Belanger <jay.p.belanger@gmail.com> | 2012-11-18 23:03:08 -0600 |
| commit | e8909bdc32f996219fe6875c837c65f891efd726 (patch) | |
| tree | 84c74c1110c117009e29fa02c8755826589dd9f5 /lisp/calc/calc-forms.el | |
| parent | 6e9f7997b36d21004794fa2b8a550729cbabd81a (diff) | |
| download | emacs-e8909bdc32f996219fe6875c837c65f891efd726.tar.gz | |
* calc/calc-forms.el (math-leap-year-p): Fix formula for negative
year numbers.
(math-date-to-julian-dt): Adjust the initial approximation for the
year to deal with the new definition of the DATE.
Diffstat (limited to 'lisp/calc/calc-forms.el')
| -rw-r--r-- | lisp/calc/calc-forms.el | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/lisp/calc/calc-forms.el b/lisp/calc/calc-forms.el index 709250f9ba9..98b22550f75 100644 --- a/lisp/calc/calc-forms.el +++ b/lisp/calc/calc-forms.el @@ -371,9 +371,10 @@ ;;; These versions are rewritten to use arbitrary-size integers. ;;; A numerical date is the number of days since midnight on -;;; the morning of December 31, 1 B.C. Emacs's calendar refers to such -;;; a date as an absolute date, some function names also use that -;;; terminology. If the date is a non-integer, it represents a specific date and time. +;;; the morning of December 31, 1 B.C. (Gregorian) or January 2, 1 A.D. (Julian). +;;; Emacs's calendar refers to such a date as an absolute date, some Calc function +;;; names also use that terminology. If the date is a non-integer, it represents +;;; a specific date and time. ;;; A "dt" is a list of the form, (year month day), corresponding to ;;; an integer code, or (year month day hour minute second), corresponding ;;; to a non-integer code. @@ -408,8 +409,8 @@ DATE is the number of days since December 31, -1 in the Gregorian calendar." (let* ((month 1) day (year (math-quotient (math-add date (if (Math-lessp date 711859) - 365 ; for speed, we take - -108)) ; >1950 as a special case + 367 ; for speed, we take + -106)) ; >1950 as a special case (if (math-negp date) 366 365))) ; this result may be an overestimate temp) @@ -494,6 +495,8 @@ Gregorian calendar." (if (math-negp year) (= (math-imod (math-neg year) 4) 1) (= (math-imod year 4) 0)) + (if (math-negp year) + (setq year (math-sub -1 year))) (setq year (math-imod year 400)) (or (and (= (% year 4) 0) (/= (% year 100) 0)) (= year 0)))) |