Here is a real simple fix so the time will display in a 12 hour format. The problem has been reported in Linux Mint 13, 14, and 15.
To fix, click on the time in the bottom menu. Click on Date and Time Settings. then copy and paste the following in the “Date format for the panel ” line:
%a %b %e,%l:%M %p
That’s it. Close the dialog box and your done.