So, if I understand this, an almanac is based on Universal Co-ordinated Time 
and if one tried to use a GPS as the time base when doing celestial, one 
would be off by 13 seconds?

I'd have to check but don't recall my watch (chronometer rated) being that far 
off from my GPS, when I use the USNO as the time standard to hack the watch.

SHould it be?







www.fer3.com/arc