1 files changed, 17 insertions, 0 deletions

diff --git a/exchange/__init__.py b/exchange/__init__.py
index a2a78ec..eafb43f 100644
--- a/exchange/__init__.py
+++ b/exchange/__init__.py
@@ -7,6 +7,23 @@ Exchange Server Handling Code
 @date: April 26, 2009
 """
 
+from datetime import tzinfo, timedelta
+
 
 class ExchangeException(Exception):
     "Exception that is thrown by all Exchange handling code."
+
+
+class AuthenticationException(ExchangeException):
+    "Exception that is raised when authentication fails."
+
+
+class EST(tzinfo):
+
+    def tzname(self, dt):
+        return "EST"
+
+    def utcoffset(self, dt):
+        return timedelta(0)
+
+    dst = utcoffset