Answer:
The answer is: The Jewish calendar with the solar calendar every 19 years in order to eliminate the difficulty of religious ceremonies varying in season.
Explanation:
The dual system was necessary because the lunar year, twelve months, is approximately eleven days shorter than the solar one. If this detail were not corrected, over the years the festivities, which constitute the central axis of Jewish history, would vary from season, a fact that would alter its character. That is why the Jewish calendar can be 12 or 13 months of 29 or 30 days, depending on the case. Thus, the years vary between 353, 354, 355, 383, 384 or 385 days.
In order to eliminate the difficulty of religious ceremonies varying from season, an extra month is periodically inserted into the calendar, so that the dates are matched.As in 19 years the solar calendar would exceed the lunar by 209 days, this is almost seven lunar months, the Jewish calendar incorporates seven leap years in that period of time.
The answer is: The Jewish calendar with the solar calendar every 19 years in order to eliminate the difficulty of religious ceremonies varying in season.