Is the Hebrew calendar lunar or solar?

Because the Hebrew calendar uses elements of both a lunar and a solar calendar, it is considered a lunisolar calendar. For the most part, the Hebrew calendar uses elements of a lunar calendar, but it does have leap years in order to bring the calendar in line with the solar cycle.

The months in the Hebrew calendar are based on the lunar cycle, but the year is based on the solar cycle, which is why leap years, which contain an extra month, are occasionally necessary. Many parts of the Hebrew calendar are defined not by astronomy but by scripture, including the length of a day, which are defined by the creation story in Genesis.