[arashf]

hmmm, I think it's fairly common practice amongst similar software (i.e. firefox, chrome, etc.) to use system time as a signal that you may be connecting to a server that has an outdated SSL certificate. while it's not perfect, it's a good first order security precaution to take (in addition to verifying the CA) to ensure you are talking to who you think you are.

[astrange]

Certificate validation for 802.1x networks relies on this, with the effect that you sometimes can't get an internet connection without fixing your clock.