IE, Unix time started then.
If the time is just used to check for certificate expiration, maybe nobody considers it worth worrying about. Which I guess is fine as far as it goes... but the other day I couldn't get Dropbox to do its thing when my clock was only a few hours off. It didn't seem likely that an SSL date check was involved in that case.
It's a common thing on school/university computers, where for various reasons, system time is always wrong and it requires Administrator privilenges to change it (I can't understand why).