[Avodah] zman hadloko erev Shabbos and motzoei Shabbos

[Zev Sero]

Michael Kopinsky wrote:
> On 1/21/07, Zev Sero <zev at sero.name> wrote:

>> ...The sun comes closest to rising at noon (which
>> is a known number of minutes before or after 12:00, depending on the date
>> but not ones location).

> What? The amount before/after noon will certainly depend on longitude
> aka position within the time zone.

Time zones are an artificial creation, which must of course be taken
into account.  But the natural time of chatzot on a given date is the
same all over the world.


> The fluctuation will depend on latitude, since I imagine that at the
> equator chatzos does not fluctuate, since there is no summer/winter.

No.  The fluctuation of noon/midnight (AKA the Equation of Time) does
not depend on the season but on the position of the earth in its
elliptical orbit, and is therefore the same everywhere.  Yes, this
means that days at the equator are not exactly 24 hours long.


-- 
Zev Sero               Something has gone seriously awry with this Court's
zev at sero.name          interpretation of the Constitution.
                       	                          - Clarence Thomas