# 247 year Jewish calendar cycle

I recently read on Matzav.com an article by Rabbi Dovid Heber discussing the 247 year cycle in the calendar. He mentioned that every 247 years the Hebrew calendar is exactly identical. Now in the article he mentions that every 247 years the Molad is almost identical. It is only a mere 905 chalakim (50 minutes and 16.67 seconds) earlier.

My question is at what point along the 247 year cycles, due to the constant slow change and creeping up in the Molad will the calendar be forced to change?

• – Isaac Moses Sep 21 '15 at 17:40
• I'm not sure I understand the question... Are you asking after how many shifts of 50 minutes = 0.83 hours, will we drift a whole day? The answer is 24/0.83 hours = 29 cycles. – Double AA Sep 21 '15 at 17:51
• @DoubleAA: At what point will the 247 year cycles not be the same anymore. – Gershon Gold Sep 21 '15 at 17:58
• @GershonGold I still don't understand what's unclear to yuou. Every cycle it drifts 50 minutes. Is that the answer you want? What about what do you want to know will be different when? – Double AA Sep 21 '15 at 18:01