Two thousand years back, this choice ended up being made regarding the fly, nearly Groundhog Day–style. Through the thirty days of Adar (which directly precedes the Passover thirty days of Nisan), the ancient rabbinical court would determine if it had been springy enough outside for Passover. If spring was on course, Nisan could take place. However, if it absolutely wasn’t warm enough outside yet, the rabbis would tack on another of Adar month. They called this month that is leap II.
Across the third century associated with Common Era, this observational system ended up being replaced with a set calendar. The Hebrew calendar now adds a jump seven years out of every 19 month. (Or, more precisely, Adar II has become added into the 3rd, sixth, eighth, 11th, 14th, 17th, and nineteenth many years of the period.)
“It works down in order for during the period of 19 years, which comes away very nearly into the amount of the years that are solar ” Dreyfus said. “But it does work that is n’t. The Jewish calendar drifts about one time later any 200 years, and thus far there is not any device to improve that.”