The helek (Hebrew חלק, meaning "portion", plural halakim חלקים) is a unit of time used in the calculation of the Hebrew calendar. The hour is divided into 1080 halakim. A helek is 31/3 seconds or 1/18 minute. The helek derives from a small Babylonian time period called a she, meaning '"barleycorn", itself equal to 1/72 of a Babylonian time degree (1° of celestial rotation).