diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -744,15 +744,16 @@ def makedate():
         tz = time.timezone
     return time.mktime(lt), tz
 
-def datestr(date=None, format='%a %b %d %H:%M:%S %Y'):
+def datestr(date=None, format='%a %b %d %H:%M:%S %Y', timezone=True):
     """represent a (unixtime, offset) tuple as a localized time.
     unixtime is seconds since the epoch, and offset is the time zone's
-    number of seconds away from UTC."""
+    number of seconds away from UTC. if timezone is false, do not
+    append time zone to string."""
     t, tz = date or makedate()
-    return ("%s %+03d%02d" %
-            (time.strftime(format, time.gmtime(float(t) - tz)),
-             -tz / 3600,
-             ((-tz % 3600) / 60)))
+    s = time.strftime(format, time.gmtime(float(t) - tz))
+    if timezone:
+        s += " %+03d%02d" % (-tz / 3600, ((-tz % 3600) / 60))
+    return s
 
 def shortuser(user):
     """Return a short representation of a user name or email address."""