From ee43ccb71e66e817d869f4819c12f5e519495c38 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 15 Feb 2010 16:46:55 -0700
Subject: [PATCH] Workaround for local timezones with historical dates on
 crippled commercial operating systems

---
 src/calibre/utils/date.py | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/calibre/utils/date.py b/src/calibre/utils/date.py
index 8b26ab02bc..da5a2d3bc2 100644
--- a/src/calibre/utils/date.py
+++ b/src/calibre/utils/date.py
@@ -11,8 +11,17 @@ from datetime import datetime
 from dateutil.parser import parse
 from dateutil.tz import tzlocal, tzutc
 
+class SafeLocalTimeZone(tzlocal):
+
+    def _isdst(self, dt):
+        try:
+            return tzlocal._isdst(self, dt)
+        except ValueError:
+            pass
+        return False
+
 utc_tz = _utc_tz = tzutc()
-local_tz = _local_tz = tzlocal()
+local_tz = _local_tz = SafeLocalTimeZone()
 
 def parse_date(date_string, assume_utc=False, as_utc=True, default=None):
     '''