Fix bug in translate_timezone and improve test.

diff --git a/datetime_utils.py b/datetime_utils.py
index 55e0ffab3b0dcedf1e6830aef38cd387d736fde0..10b166605570b14332fe7c7f5ebf74b645a05960 100644 (file)
--- a/datetime_utils.py
+++ b/datetime_utils.py
@@ -200,19 +200,22 @@ def translate_timezone(dt: datetime.datetime, tz: datetime.tzinfo) -> datetime.d
     day, hour, minute, second, micro, etc... appropriately.  The returned
     dt is the same instant in another timezone.
 
-    >>> from pytz import UTC
+    >>> import pytz
     >>> d = now_pacific()
     >>> d.tzinfo.tzname(d)[0]     # Note: could be PST or PDT
     'P'
     >>> h = d.hour
-    >>> o = translate_timezone(d, UTC)
-    >>> o.tzinfo.tzname(o)
-    'UTC'
+    >>> o = translate_timezone(d, pytz.timezone('US/Eastern'))
+    >>> o.tzinfo.tzname(o)[0]     # Again, could be EST or EDT
+    'E'
     >>> o.hour == h
     False
-
+    >>> expected = h + 3          # Three hours later in E?T than P?T
+    >>> expected = expected % 24  # Handle edge case
+    >>> expected == o.hour
+    True
     """
-    return dt.replace(tzinfo=None).astimezone(tz=tz)
+    return dt.replace().astimezone(tz=tz)
 
 
 def now() -> datetime.datetime: