Negative result of django.utils.timesince.timesince

[Lorenzo Peña]

Reproducible example:

import zoneinfo
import datetime as _dt
from django.utils.timesince import timesince
import django.utils.timezone as _timezone

timesince(_timezone.now().astimezone(zoneinfo.ZoneInfo(key='Europe/Berlin'))-_dt.timedelta(seconds=1))

>>> '-1\xa0Year, 11\xa0Months'

[Mariusz Felisiak]

Thanks for the report.

Regression in 8d67e16493c903adc9d049141028bc0fff43f8c8.
Reproduced at 3b4728310a7a64f8fcc548163b0aa5f98a5c78f5.

[GitHub <noreply@…>]

In 813015d:

Fixed #34483 -- Fixed timesince()/timeuntil() with timezone-aware dates and interval less than 1 day.

Regression in 8d67e16493c903adc9d049141028bc0fff43f8c8.

Thanks Lorenzo Peña for the report.

[Natalia <124304+nessita@…>]

In a3c14ea:

[4.2.x] Fixed #34483 -- Fixed timesince()/timeuntil() with timezone-aware dates and interval less than 1 day.

Regression in 8d67e16493c903adc9d049141028bc0fff43f8c8.

Thanks Lorenzo Peña for the report.

Backport of 813015d67e2557fa859a07930a9becec4e5f64a0 from main

[Mariusz Felisiak]

It seems that there is still an issue when a time difference is less than 1 day but days are different, see ​logs.

[GitHub <noreply@…>]

In cd464fbc:

[4.2.x] Refs #34483 -- Fixed utils_tests.test_timesince crash on Python 3.8.

[Mariusz Felisiak]

It seems that now must be in the same time zone (as you suggested at the beginning), however we also have to change time zone when now is passed, e.g.

django/utils/timesince.py

@@ -63 +63 @@
     if now and not isinstance(now, datetime.datetime):
         now = datetime.datetime(now.year, now.month, now.day)
 
-    now = now or datetime.datetime.now(datetime.timezone.utc if is_aware(d) else None)
+    if is_aware(d):
+        now = now.astimezone(d.tzinfo) if now else datetime.datetime.now(tz=d.tzinfo)
+    else:
+        now = now or datetime.datetime.now()
 
     if reversed:
         d, now = now, d
@@ -77 +80 @@
 
     # Get years and months.
     total_months = (now.year - d.year) * 12 + (now.month - d.month)
-    time_delta = delta - datetime.timedelta(days=delta.days)
-    if d.day > now.day or (d.day == now.day and time_delta.total_seconds() < 0):
+    if d.day > now.day or (d.day == now.day and d.time() > now.time()):
         total_months -= 1
     years, months = divmod(total_months, 12)
 

see a regression test:

tests/utils_tests/test_timesince.py

@@ -258 +258 @@
             with self.subTest(value):
                 self.assertEqual(timesince(value), expected)
 
+    @requires_tz_support
+    def test_less_than_a_day_cross_day_with_zoneinfo(self):
+        now_with_zoneinfo = timezone.make_aware(
+            datetime.datetime(2023, 4, 14, 1, 30, 30),
+            zoneinfo.ZoneInfo(key="Asia/Kathmandu")  # UTC+05:45
+        )
+        now_utc = now_with_zoneinfo.astimezone(datetime.timezone.utc)
+        tests = [
+            (now_with_zoneinfo, "0\xa0minutes"),
+            (now_with_zoneinfo - self.onemicrosecond, "0\xa0minutes"),
+            (now_with_zoneinfo - self.onesecond, "0\xa0minutes"),
+            (now_with_zoneinfo - self.oneminute, "1\xa0minute"),
+            (now_with_zoneinfo - self.onehour, "1\xa0hour"),
+        ]
+        for value, expected in tests:
+            with self.subTest(value):
+                self.assertEqual(timesince(value, now_utc), expected)
+
 
 @requires_tz_support
 @override_settings(USE_TZ=True)

What do you think?

[Mariusz Felisiak]

​PR

[GitHub <noreply@…>]

In 198a19b6:

Refs #34483 -- Fixed timesince()/timeuntil() with timezone-aware dates on different days and interval less than 1 day.

Follow up to 813015d67e2557fa859a07930a9becec4e5f64a0.
Regression in 8d67e16493c903adc9d049141028bc0fff43f8c8.

[Mariusz Felisiak <felisiak.mariusz@…>]

In f75a6977:

[4.2.x] Refs #34483 -- Fixed timesince()/timeuntil() with timezone-aware dates on different days and interval less than 1 day.

Follow up to 813015d67e2557fa859a07930a9becec4e5f64a0.
Regression in 8d67e16493c903adc9d049141028bc0fff43f8c8.
Backport of 198a19b692699ad3940373d9ed797fe9155f3f4a from main