On Feb 20, 2:30*pm, wrote:
On Fri, 20 Feb 2009 09:31:06 -0600, dpb wrote:
wrote:
...

* * * *I have seen both radio signal and pre-set internal battery
powered clocks. *It might be either. *

How did they know which time zone to preset it to????

And how does it deal with Daylight Savings on and off?

If it syncs to NIST, it gets a signal as to whether DST is in effect
or not when it syncs. (well, it SHOULD, there is a DST flag. I guess
some clocks may be pre-set for DST changes, in which case older ones
will not work correctly now that we've been mucking about with it. I
do know that my "Sharp" alarm clock handles DST correctly, that is, it
gets its DST flag from the NIST signal not from its internal
programming.)

nate