Yosi Rosenblum was born in Tel Aviv about 10:30 PM on a date (mm.dd.yyyy) claiming maximal sum of digits.
On what date (mm.dd.yyyy) will he become Bar Mizvah?
It is my understanding that:
1) Yes, Jewish days start at sunset (please don't ask me which sunset), not at moonrise. If they did start at moonrise, then the average day would be about 24.75 hours, and days would sometimes switch at 10am or noon or 2:30am, all of which would be a problem.
2) Incidentally, it is considered a lunisolar calendar, not a lunar calendar.
3) Moonrise does come into play slightly in determining the months. The months were calculated to begin on the sunset immediately preceding the first appearance of the crescent moon, but even here the moonrise is not exactly the determining factor, since the new moon and then the first crescent moon can take place during daylight hours.
Edited on July 7, 2011, 11:39 pm