--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/cm/utils/timezone.py	Mon Nov 23 15:14:29 2009 +0100
@@ -0,0 +1,31 @@
+from datetime import timedelta
+from pytz import timezone, utc
+from django.conf import settings
+
+local_tz = timezone(settings.TIME_ZONE)
+
+def request_tz_convert(date, request):
+    return tz_convert(date, request.session.get('tz',None))
+
+def tz_convert(date, tz):
+    """
+    Convert date to time zone
+    tz can be;
+        - '-2' (relative to utc)
+        - 'Paris/Europe' real timezone like (cf pytz)
+    """
+    if tz:
+        system_local_date = local_tz.localize(date)
+        try:
+             # simple utc delta?
+            utc_offset = int(tz)
+            utc_time = system_local_date.astimezone(utc)
+            res = utc.normalize(utc_time + timedelta(hours=utc_offset))
+            return res
+        except:
+            # real timezone
+            timez = timezone(tz)
+            local_date = system_local_date.astimezone(timez)
+            return local_date            
+    else:
+        return date