From: John Keith Hohm <john@hohm.net>
Date: Mon, 19 May 2025 20:48:55 +0000 (-0400)
Subject: gh-88994: Change `datetime.datetime.now` to half-even rounding (#134258)
X-Git-Tag: v3.15.0a1~1650
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=470941782f74288823b445120f6383914b659f23;p=thirdparty%2FPython%2Fcpython.git

gh-88994: Change `datetime.datetime.now` to half-even rounding (#134258)

Change `datetime.datetime.now` to half-even rounding
for consistency with `datetime.fromtimestamp`.
---

diff --git a/Misc/ACKS b/Misc/ACKS
index 5653c52c9e35..1b500870dec4 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -795,6 +795,7 @@ Albert Hofkamp
 Chris Hogan
 Tomas Hoger
 Jonathan Hogg
+John Keith Hohm
 Vladyslav Hoi
 Kamilla Holanda
 Steve Holden
diff --git a/Misc/NEWS.d/next/Library/2025-05-19-18-12-42.gh-issue-88994.7avvVu.rst b/Misc/NEWS.d/next/Library/2025-05-19-18-12-42.gh-issue-88994.7avvVu.rst
new file mode 100644
index 000000000000..554a0c3bcb26
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-05-19-18-12-42.gh-issue-88994.7avvVu.rst
@@ -0,0 +1,3 @@
+Change :func:`datetime.datetime.now` to half-even rounding for
+consistency with :func:`datetime.datetime.fromtimestamp`.  Patch by
+John Keith Hohm.
diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c
index 313a72e3fe06..eb90be81c8d3 100644
--- a/Modules/_datetimemodule.c
+++ b/Modules/_datetimemodule.c
@@ -5551,8 +5551,9 @@ datetime_best_possible(PyObject *cls, TM_FUNC f, PyObject *tzinfo)
     time_t secs;
     int us;
 
-    if (_PyTime_AsTimevalTime_t(ts, &secs, &us, _PyTime_ROUND_FLOOR) < 0)
+    if (_PyTime_AsTimevalTime_t(ts, &secs, &us, _PyTime_ROUND_HALF_EVEN) < 0) {
         return NULL;
+    }
     assert(0 <= us && us <= 999999);
 
     return datetime_from_timet_and_us(cls, f, secs, us, tzinfo);