[Avodah] Molad

[Zev Sero via Avodah]

On 07/28/2015 12:41 PM, Allan Engel via Avodah wrote:
> Calendars in my home town print the latest times of saying Kiddush
> Levana, which equate to exactly fifteen days after the announced
> Molad time. This might be an entire night, or an exact time, e.g.
> Sunday night 22.45.

That should be halfway between moldos, i.e. 14d 18h 22m after the
molad, not a full 15 days.  It should also be adjusted for the time
difference between your standard time and Y'm's real time, which
for NY is 7h 20m in the winter and 6h 20m in the summer.   Using
a full 15 days is only bediavad.


> But since the astronomical Molad can be some distance from the
> calculated Molad times, by sometimes as much as twelve hours, does
> this not mean that these sof zeman kiddush levana times can be faulty
> by that same margin?

Yes, but since we have no easy way (other than consulting readily-
available secular resources, of course) of determining when the real
full moon occurs, we use the calculated moldos, *unless* there is a
lunar eclipse, since that by definition happens at the true full moon.


-- 
Zev Sero               I have a right to stand on my own defence, if you
zev at sero.name          intend to commit felony...if a robber meets me in
                        the street and commands me to surrender my purse,
                        I have a right to kill him without asking questions
                                               -- John Adams