[Avodah] zman hadloko erev Shabbos and motzoei Shabbos

[Michael Kopinsky]

On 1/23/07, Zev Sero <zev at sero.name> wrote:
> Michael Kopinsky wrote:
> > 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.

Do you mean 12 hours (ie that there isn't a perpetual equinox, as I had
thought), or 24 (that the *rotation* of the earth isn't constant)?