>>I know about that - I should have been more specific. Where are the time lines in the USA. Are they along state lines, are they signposted? If you drive over one does it say so? Just interested is all.
>
>I've been across country, but I don't recall too well. I think I've encountered some time-change signs...but it's usually on the maps when you're traveling, so you notice it there, that I do recall...

I've driven across the country more than once. There are no signs!!
Most of the time zones here in the USA are done by state lines where
possible. But there are exceptions. There is one small town in
Indiana that refuses to accept summer daylight time. There is another
small town in Texas that chnages the time two hours in order to take advantage of the added light.
How do you know what time it is?? You stop off for coffee or tea and look at the clock