diff options
Diffstat (limited to 'Lib/test/test_datetime.py')
| -rw-r--r-- | Lib/test/test_datetime.py | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/Lib/test/test_datetime.py b/Lib/test/test_datetime.py index 4a7aa60..4fe2ad2 100644 --- a/Lib/test/test_datetime.py +++ b/Lib/test/test_datetime.py @@ -2703,6 +2703,31 @@ class TestTimezoneConversions(unittest.TestCase): # self.convert_between_tz_and_utc(Eastern, Central) # can't work # self.convert_between_tz_and_utc(Central, Eastern) # can't work + def test_tricky(self): + # 22:00 on day before daylight starts. + fourback = self.dston - timedelta(hours=4) + ninewest = FixedOffset(-9*60, "-0900", 0) + fourback = fourback.astimezone(ninewest) + # 22:00-0900 is 7:00 UTC == 2:00 EST == 3:00 DST. Since it's "after + # 2", we should get the 3 spelling. + # If we plug 22:00 the day before into Eastern, it "looks like std + # time", so its offset is returned as -5, and -5 - -9 = 4. Adding 4 + # to 22:00 lands on 2:00, which makes no sense in local time (the + # local clock jumps from 1 to 3). The point here is to make sure we + # get the 3 spelling. + expected = self.dston.replace(hour=3) + got = fourback.astimezone(Eastern).astimezone(None) + self.assertEqual(expected, got) + + # Similar, but map to 6:00 UTC == 1:00 EST == 2:00 DST. In that + # case we want the 1:00 spelling. + sixutc = self.dston.replace(hour=6).astimezone(utc_real) + # Now 6:00 "looks like daylight", so the offset wrt Eastern is -4, + # and adding -4-0 == -4 gives the 2:00 spelling. We want the 1:00 EST + # spelling. + expected = self.dston.replace(hour=1) + got = sixutc.astimezone(Eastern).astimezone(None) + self.assertEqual(expected, got) def test_suite(): allsuites = [unittest.makeSuite(klass, 'test') |