fix custom-formats with timezone

dateparser/utils/__init__.py

@@ -121,22 +121,29 @@ def apply_timezone(date_time, tz_string):
 
 
 def apply_timezone_from_settings(date_obj, settings):
-    tz = get_localzone()
     if settings is None:
         return date_obj
 
-    if 'local' in settings.TIMEZONE.lower():
-        if hasattr(tz, 'localize'):
-            date_obj = tz.localize(date_obj)
+    is_originally_aware = is_aware(date_obj)
+
+    if not is_originally_aware:
+        if 'local' in settings.TIMEZONE.lower():
+            tz = get_localzone()
+            if hasattr(tz, 'localize'):
+                date_obj = tz.localize(date_obj)
+            else:
+                date_obj = date_obj.replace(tzinfo=tz)
         else:
-            date_obj = date_obj.replace(tzinfo=tz)
-    else:
-        date_obj = localize_timezone(date_obj, settings.TIMEZONE)
+            date_obj = localize_timezone(date_obj, settings.TIMEZONE)
 
     if settings.TO_TIMEZONE:
         date_obj = apply_timezone(date_obj, settings.TO_TIMEZONE)
 
-    if settings.RETURN_AS_TIMEZONE_AWARE is not True:
+    if (
+        not settings.RETURN_AS_TIMEZONE_AWARE
+        or (settings.RETURN_AS_TIMEZONE_AWARE
+            and 'default' == settings.RETURN_AS_TIMEZONE_AWARE and not is_originally_aware)
+    ):
         date_obj = date_obj.replace(tzinfo=None)
 
     return date_obj
@@ -235,3 +242,15 @@ def setup_logging():
         },
     }
     logging.config.dictConfig(config)
+
+
+def is_aware(date_obj):
+    """
+    From Python docs (https://docs.python.org/3/library/datetime.html#determining-if-an-object-is-aware-or-naive):
+
+    A datetime object d is aware if both of the following hold:
+    1. d.tzinfo is not None
+    2. d.tzinfo.utcoffset(d) does not return None
+
+    """
+    return date_obj.tzinfo is not None and date_obj.tzinfo.utcoffset(date_obj) is not None

tests/test_date.py

@@ -3,7 +3,7 @@
 import unittest
 from collections import OrderedDict
 from copy import copy
-from datetime import datetime, timedelta
+from datetime import datetime, timedelta, timezone
 
 from unittest.mock import Mock, patch
 from parameterized import parameterized, param
@@ -12,6 +12,7 @@
 from dateparser.date import DateData
 from dateparser import date
 from dateparser.conf import settings
+from dateparser.timezone_parser import StaticTzInfo
 
 from tests import BaseTestCase
 
@@ -258,6 +259,23 @@ def test_should_parse_date(self, date_string, date_formats, expected_result):
         self.then_parsed_period_is('day')
         self.then_parsed_date_is(expected_result)
 
+    @parameterized.expand([
+        param(date_string='Fri Jan 26 16:32:21 +0000 2018', date_formats=['%a %b %d %H:%M:%S %z %Y'],
+              expected_result=datetime(2018, 1, 26, 16, 32, 21)),
+        param(date_string='15/04/1904 14:05 +0004', date_formats=['%d/%m/%Y %H:%M %z'],
+              expected_result=datetime(1904, 4, 15, 14, 5, tzinfo=timezone(timedelta(0, 240)))),
+        param(
+            date_string='20-05-1994 23:00 GMT', date_formats=['%d-%m-%Y %H:%M %Z'], expected_result=datetime(
+                1994, 5, 20, 23, 0, tzinfo=StaticTzInfo('GMT', timedelta(seconds=0))
+            )
+        ),
+    ])
+    def test_should_parse_localized_dates(self, date_string, date_formats, expected_result):
+        self.when_date_is_parsed_with_formats(date_string, date_formats)
+        self.then_date_was_parsed()
+        self.then_parsed_period_is('day')
+        self.then_parsed_date_is(expected_result)
+
     @parameterized.expand([
         param(date_string='09.16', date_formats=['%m.%d'], expected_month=9, expected_day=16),
     ])