Comment 3 for bug 1005575

Yes, this just happened to us when I was setting up Mint 14 Cinnamon on my son's PC.

Unbeknownst to me, my son opened the Date and Time Settings and changed the customizable format variables (in the "Date and time format for the panel" box). He didn't want the date to appear on his panel, only only the time—so he removed the date variables. From that point on, the clock refused to update.

When we restored some date variables, that fixed it. So apparently the app expects both date and time variables in that string, no matter what.