Another thing to consider is if Mac OS uses software driven time configuration. Windows tends to read the BIOS time, if for some reason that has changed it could very well cause similar issues. To boot into the BIOS
- Turn your machine on and wait a few seconds for the splash screen to appear
- Look for "Press ... to enter setup" (... can be F1, F2, F10 or Del).
- Once in the BIOS look for the basic settings and make sure that the time/date is set correctly
Navigation keys/instructions will be shown on the Right/Bottom of the screen