Index: trac/Timeline.py
===================================================================
--- trac/Timeline.py	(revision 4204)
+++ trac/Timeline.py	(working copy)
@@ -138,6 +138,13 @@
         stop = fromdate
         start = stop - (daysback + 1) * 86400
 
+        try:
+            repos = self.env.get_repository()
+        except TracError:
+            pass # Unsupported version control
+        else:
+            repos.sync()
+
         events = []
         for event_provider in self.event_providers:
             try: