Pet peeve - DTV clocks

[CAwasinNJ]

Why is it that some TV stations don't keep their clocks set correctly? The major stations do, so thank you. But what of the others? KTMW is close (only off by 2 minutes), but others are off by a lot. KSVN and K39JS are both off by exactly 4 hours. (Timezone must be mis-set.) And the winner for most screwed up is KPNZ, off by 8 1/2 hours. Is it just me or does that kind of not paying attention make you feel like the station doesn't care?

[kenglish]

It depends on where they get their "time" from, and how they keep it accurate.
PSIP generators can get the time from their computer's internal clock, which then is subject to power failures, etc.
They can get it from the computer network's SNTP server, or they can get it from the National Bureau of Standards (now called the NIST, National Institute of Standards and Technology).
I guess some PSIP generators can use all, some can't.