[time-nuts] Time-zones and World time..

Lux, James P james.p.lux at jpl.nasa.gov
Thu Oct 30 19:17:07 UTC 2008



> -----Original Message-----
> From: time-nuts-bounces at febo.com
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Chuck Harris
> Sent: Thursday, October 30, 2008 12:09 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Time-zones and World time..
>
> As I recall, Local Solar Time is also known as Apparent Solar
> Time, and is defined as when the sun reaches its highest
> point over some local meridian of interest (town hall?).
>
> That point in time is called 00:00:00... Which sort of makes
> sense because you can directly observe high-noon, but
> midnight can only be estimated.
>
> -Chuck Harris
>
One can, of course, observe meridian passage for a variety of stars at night, and from that determine the time (given a calendar and the appropriate almanac data), so you could directly observe midnight.

Don't forget too, that solar noon varies quite a bit (minutes) from "mean solar time" over the year.  If you're navigating your ship with noon sun sights, this is pretty important.



More information about the time-nuts mailing list