Network clocks

It just seems strange to me that network clocks should show as much variance as they do. I mean, not all the network clocks I use are exactly synchronized; my computer (Apple) and mobile phone (Sprint) aren't precisely matched—the difference is a couple of seconds. Big deal. These times are only seconds removed (less than five, as far as I can tell), from Comcast's digital cable television signal. And whatever network my brother uses to regulate the time on his Windows-based PC is also within mere seconds of the rest.

So I'm accustomed to network clocks on diverse networks being pretty close to one another. Wordpress and Google, my two blog hosts, are very close, as well. (Would Google run its own network clock, or would they look to someone else's?)

But there are a couple of clocks I see in my regular internet habits that run between three and five minutes off, and that seems a pretty big variance. The difference manifests itself in time-stamps, such as in posting comments to a news article. I can understand a minute's difference, as one clock rounds the circle first, but three minutes? Five minutes? That's pretty wild.

Not that it's tremendously important. I just think it's weird.