Make test_dates.py robust to daylight saving.

Author: domdfcoding

tests/test_dates.py

@@ -32,15 +32,25 @@ def test_utc_offset():
 	# TODO: Finish
 
 	# Check that the correct UTC offsets are given for common timezones for today
-	assert dates.get_utc_offset("US/Pacific", today) == datetime.timedelta(-1, 61200)
-	# assert dates.get_utc_offset("Europe/London", today) == datetime.timedelta(0, 3600)  # BST
-	assert dates.get_utc_offset("Europe/London", today) == datetime.timedelta(0, 0)
+	assert dates.get_utc_offset("US/Pacific", today) in {
+			datetime.timedelta(-1, 57600),
+			datetime.timedelta(-1, 61200),
+			}
+	assert dates.get_utc_offset("Europe/London", today) in {
+			datetime.timedelta(0, 3600),  # BST
+			datetime.timedelta(0, 0),
+			}
 	assert dates.get_utc_offset("Africa/Algiers", today) == datetime.timedelta(0, 3600)
 
 	# Check that the correct UTC offsets are given for common timezones when ``date`` is not given
-	assert dates.get_utc_offset("US/Pacific") == datetime.timedelta(-1, 61200)
-	# assert dates.get_utc_offset("Europe/London") == datetime.timedelta(0, 3600)  # BST
-	assert dates.get_utc_offset("Europe/London") == datetime.timedelta(0, 0)
+	assert dates.get_utc_offset("US/Pacific") in {
+			datetime.timedelta(-1, 57600),
+			datetime.timedelta(-1, 61200),
+			}
+	assert dates.get_utc_offset("Europe/London") in {
+			datetime.timedelta(0, 3600),  # BST
+			datetime.timedelta(0, 0),
+			}
 	assert dates.get_utc_offset("Africa/Algiers") == datetime.timedelta(0, 3600)