How many days are in a leap year in the Jewish calendar?

Answer 1

Unlike the secular January to December calendar, which is based entirely on the solar cycle, the Hebrew calendar is based on both the solar and lunar cycles.

Since solar and lunar cycles do not match (a solar year being approximately eleven days longer than twelve lunar months), this results in Hebrew years of varying length over a nineteen year Metonic cycle of 235 months with an extra "leap month" added every two or three years for a total of seven times in every nineteen years - this is known as Adar II and comes just before the month of Nisan, with the "II" added to distinguish it from Adar Aleph ("the first Adar"). Each of these nineteen year periods can be either 6939, 6940, 6941 or 6942 days in total - none of which can be divided by seven, so that the Metonic cycles themselves follow a pattern lasting for 36,288 cycles, or 689,472 Jewish years. This means that a Hebrew year can have either 353, 354, 355, 383, 384 or 385 days.

Complicated, isn't it? In the past, rabbis and Jews with really quite phenomenal mathematical skills laboured long and hard to work out the complexities of the Hebrew calendar - thankfully computers have made it all a lot simpler.

Answer 2

There are 354 days, but a leap month is added 7 times every 19 years to keep the seasons aligned.

Answer 3

383.