Fix timezone bug for ATOM generation

pelican/utils.py

@@ -4,6 +4,7 @@ import os
 import shutil
 import time
 import calendar
+import pytz
 from datetime import datetime
 from codecs import open as _open
 from itertools import groupby
@@ -225,9 +226,12 @@ def files_changed(path, extensions):
         return True
     return False
 
-def local_to_utc(t):
-    "Convert article time to UTC time for ATOM feeds"
-    secs = time.mktime(t)
-    gmtime = list(time.gmtime(secs))
-    gmtime[8] = 1
-    return datetime.fromtimestamp(time.mktime(gmtime))
+def set_date_tzinfo(d, tz_name=None):
+    """ Date without tzinfo shoudbe utc.
+    This function set the right tz to date that aren't utc and don't have tzinfo
+    """
+    if tz_name is not None:
+        tz = pytz.timezone(tz_name)
+        return tz.localize(d)
+    else:
+        return d