1 files changed, 14 insertions, 26 deletions
diff --git a/django/utils/dateformat.py b/django/utils/dateformat.py
index 9bd05a437b..38e89c47bb 100644
--- a/django/utils/dateformat.py
+++ b/django/utils/dateformat.py
@@ -20,7 +20,8 @@ from django.utils.dates import (
 )
 from django.utils.regex_helper import _lazy_re_compile
 from django.utils.timezone import (
-    get_default_timezone, is_aware, is_naive, make_aware,
+    _datetime_ambiguous_or_imaginary, get_default_timezone, is_aware, is_naive,
+    make_aware,
 )
 from django.utils.translation import gettext as _
 
@@ -160,15 +161,9 @@ class TimeFormat(Formatter):
         if not self.timezone:
             return ""
 
-        name = None
-        try:
+        if not _datetime_ambiguous_or_imaginary(self.data, self.timezone):
             name = self.timezone.tzname(self.data)
-        except Exception:
-            # pytz raises AmbiguousTimeError during the autumn DST change.
-            # This happens mainly when __init__ receives a naive datetime
-            # and sets self.timezone = get_default_timezone().
-            pass
-        if name is None:
+        else:
             name = self.format('O')
         return str(name)
 
@@ -184,16 +179,13 @@ class TimeFormat(Formatter):
 
         If timezone information is not available, return an empty string.
         """
-        if not self.timezone:
+        if (
+            not self.timezone or
+            _datetime_ambiguous_or_imaginary(self.data, self.timezone)
+        ):
             return ""
 
-        try:
-            offset = self.timezone.utcoffset(self.data)
-        except Exception:
-            # pytz raises AmbiguousTimeError during the autumn DST change.
-            # This happens mainly when __init__ receives a naive datetime
-            # and sets self.timezone = get_default_timezone().
-            return ""
+        offset = self.timezone.utcoffset(self.data)
 
         # `offset` is a datetime.timedelta. For negative values (to the west of
         # UTC) only days can be negative (days=-1) and seconds are always
@@ -232,16 +224,12 @@ class DateFormat(TimeFormat):
 
     def I(self):  # NOQA: E743, E741
         "'1' if Daylight Savings Time, '0' otherwise."
-        try:
-            if self.timezone and self.timezone.dst(self.data):
-                return '1'
-            else:
-                return '0'
-        except Exception:
-            # pytz raises AmbiguousTimeError during the autumn DST change.
-            # This happens mainly when __init__ receives a naive datetime
-            # and sets self.timezone = get_default_timezone().
+        if (
+            not self.timezone or
+            _datetime_ambiguous_or_imaginary(self.data, self.timezone)
+        ):
             return ''
+        return '1' if self.timezone.dst(self.data) else '0'
 
     def j(self):
         "Day of the month without leading zeros; i.e. '1' to '31'"