4
votes
1answer
261 views

When was the last time the “Leap Year” postponement rule was used to delay the date of Rosh Hashannah?

This site explains that there are 4 rules that would cause Rosh Hashannah to be postponed 1 or 2 days after the date of Molad Tishrei. You can view all 4 rules on the web site, but rule 4 states: ...
6
votes
0answers
55 views

Historical Calendar Records

Are there any records of the Beis Din's decisions regarding the Hebrew Calendar (e.g. to add months, how long the month would be), before Hillel Hakatan established the fixed calendar?
4
votes
1answer
242 views

Rambam's method for calculating the conjunction of the moon (and sun)

I think I'm missing something basic here... The Rambam, in Hilchot Kiddush Hachodesh (6:3) says that the interval between one conjunction to the next is is 29 full days, 12 hours of the 30th day, and ...
1
vote
1answer
127 views

What was the first Hebrew date of the first Molad?

If one were to represent the Molad Tohu as a date, comprised of a month, day, year, hours, minutes, seconds, and chalakim, what date would that be?
2
votes
0answers
54 views

If a Beis Din Makes a Mistake When Calculating Kiddush HaChodesh, Does it Count?

On one hand, the Rambam says (in 2:10) Once the court sanctifies the new month, it remains sanctified regardless of whether they erred unwittingly, they were led astray [by false witnesses], or ...