4 files changed, 23 insertions, 7 deletions
diff --git a/src/mongo/unittest/unittest_helpers.cpp b/src/mongo/unittest/unittest_helpers.cpp
index 0ae120f0581..450a1b2146e 100644
--- a/src/mongo/unittest/unittest_helpers.cpp
+++ b/src/mongo/unittest/unittest_helpers.cpp
@@ -41,9 +41,4 @@ std::ostream& operator<<(std::ostream& s, const Timestamp& ot) {
     s << ot.toString();
     return s;
 }
-
-std::ostream& operator<<(std::ostream& s, const Date_t& t) {
-    s << t.toString();
-    return s;
-}
 }
diff --git a/src/mongo/unittest/unittest_helpers.h b/src/mongo/unittest/unittest_helpers.h
index 0a90ec0cec1..c02d2c35853 100644
--- a/src/mongo/unittest/unittest_helpers.h
+++ b/src/mongo/unittest/unittest_helpers.h
@@ -37,7 +37,5 @@ class Date_t;
 // So that you can ASSERT_EQUALS two Timestamps
 std::ostream& operator<<(std::ostream& s, const Timestamp& ot);
 
-// So that you can ASSERT_EQUALS two Date_ts
-std::ostream& operator<<(std::ostream& s, const Date_t& t);
 
 }  // namespace mongo
diff --git a/src/mongo/util/time_support.h b/src/mongo/util/time_support.h
index 203001e58fa..d9c1821dd3f 100644
--- a/src/mongo/util/time_support.h
+++ b/src/mongo/util/time_support.h
@@ -219,6 +219,11 @@ public:
         return !(*this < other);
     }
 
+    friend std::ostream& operator<<(std::ostream& out, const Date_t& date) {
+        out << date.toString();
+        return out;
+    }
+
 private:
     constexpr explicit Date_t(long long m) : millis(m) {}
 
diff --git a/src/mongo/util/time_support_test.cpp b/src/mongo/util/time_support_test.cpp
index 24052f3f147..0d7f6b875b9 100644
--- a/src/mongo/util/time_support_test.cpp
+++ b/src/mongo/util/time_support_test.cpp
@@ -820,6 +820,24 @@ TEST(TimeFormatting, DurationFormatting) {
     ASSERT_EQUALS("52ms52\xce\xbcs52s", os.str());
 }
 
+TEST(TimeFormatting, WriteToStream) {
+    const std::vector<std::string> dateStrings = {
+        "1996-04-07T00:00:00.000Z",
+        "1996-05-02T00:00:00.000Z",
+        "1997-06-23T07:55:00.000Z",
+        "2015-05-14T17:28:33.123Z",
+        "2036-02-29T00:00:00.000Z",
+    };
+
+    for (const std::string& isoTimeString : dateStrings) {
+        const Date_t aDate = unittest::assertGet(dateFromISOString(isoTimeString));
+        std::ostringstream testStream;
+        testStream << aDate;
+        std::string streamOut = testStream.str();
+        ASSERT_EQUALS(aDate.toString(), streamOut);
+    }
+}
+
 TEST(SystemTime, ConvertDateToSystemTime) {
     const std::string isoTimeString = "2015-05-14T17:28:33.123Z";
     const Date_t aDate = unittest::assertGet(dateFromISOString(isoTimeString));