Nisan

Nisan (; ) or Nissan (; from ) is the month of the barley ripening and the first month of spring in the Babylonian and Hebrew calendars. The name of the month is an Akkadian borrowing, although it is ultimately derived from Sumerian nisag 'first fruits'.

Annual holiday commemorating the Assyrian New Year

The ceremonial 'search for chametz' done the evening prior to the 1st night of Passover.