I found this George Burns reference and was puzzled by it. As far as I know, I don't use any kind of synchronizing service.

Users>myname>Library>Logs>Sync>syncservices.log:


2015-06-28 12:45:28:001|SyncServer|201|110f40|SyncServer|Warning| Refreshing watchdog because of a calendar time change alert.
2015-06-28 12:47:28:800|SyncServer|201|110f40|Server|Info| Cancelling all sync plans.
2015-06-28 12:47:28:802|SyncServer|201|110f40|Server|Info| Goodnight, Gracie.

"Goodnight Gracie" appears numerous times in my log...a programmer's joke response to some event (that I can't discern), I imagine.

I'm running 10.6.8, and I've had that log for as long as I can remember, but I've never investigated its purpose.