Pachyderm is a small utility that quickly checks your system clock to make sure it's sane. This can help workaround the occasional problem where a machine has its clock reset to January 1, 1970 after rebooting.
To use it, simply run it. If Pachyderm thinks your system closk is screwed up, it will ask you to change or confirm it. If the system clock seems OK, Pachyderm will exit without any user action.