This is the name of the first month of the year in the Torah—the month of Nisan.
This month marks the holiday of Passover, which Jewish tradition dictates should coincide with spring in the Land of Israel.
However, because the Jewish lunar calendar lags behind the solar calendar by 11 days (the solar calendar has 365 days, while the Jewish lunar calendar has 354 days), an extra month, Adar, is introduced every two or three years, bringing the months of Nisan and Passover closer to spring in the Land of Israel.