The length of the year (was:RE: barred-h)

Christophe Grandsire <grandsir@...> wrote:
>         BTW, talking of constants, does anyone knows the exact length of the
> Earth year in days (with as many decimals as possible) or at least knows
> an URL where I can find it? I want to make a personal calendar to go
> with my personal language and I need to know that. I know this would be
> better posted on conculture-l, but I prefer not subscribing to it with
> this address (I have to much real life work to do), and I can't use my
> other addresses as much.
The Gregorian system assumes a year of 365d 5h 49m 15s.

The 'tropic year' is 365d 5h 48m 46s = 365.2422 days. It's the time between
two consecutive spring equinoxes, but it gets 0.53s shorter every year, so
the base year is 1900. This is the main time measure, and it served to
fix the definition of a second (I think a second is measured by other
means).

The sidereal day (time between two consecutive passes of a particular
star through the meridian of the place) is in average 23h 56m 4.09s
(+/-0.01s). What I don't know is whether or not the 'day' mentioned in
the year definitions is *this* year, or the usual 24h day.

Hope that helps,


--Pablo Flores