{{short description|Time measurement in Jewish tradition}} {{refimprove|date=January 2021}} The '''helek''', also spelled '''chelek''' (Hebrew חלק, meaning "portion", plural ''halakim'' חלקים) is a unit of time used in the calculation of the Molad. Other spellings used are ''chelak'' and ''chelek'', both with plural ''chalakim''.
An hour is divided into 1080 halakim. A helek is 3{{sfrac|1|3}} seconds or <sup>1</sup>/<sub>18</sub> minute. The ''helek'' derives from a small Babylonian time period called a ''she'', meaning '"barleycorn", itself equal to <sup>1</sup>/<sub>72</sub> of a Babylonian time degree (1° of celestial rotation).
:360 degrees × 72 ''shes'' per degree / 24 hours = 1080 ''shes'' per hour.
The Hebrew calendar defines its mean month to be exactly equal to 29 days 12 hours and 793 halakim, which is 29 days 12 hours 44 minutes and 3{{sfrac|1|3}} seconds. It defines its mean year as exactly 235/19 times this amount, or 365 days, 5 hours, 55 minutes, and 25 and 25/57 seconds (approximately 365.2468222 days).
== Bibliography == * {{Cite web|title=Molad Times - For the Jewish Years 5780 & 5781 (2020-2021)|url=https://www.chabad.org/library/article_cdo/aid/216238/jewish/Molad-Times.htm|access-date=2021-01-31|website=www.chabad.org|language=en}} * {{Cite web|title=The Jewish calendar|url=https://faculty1.coloradocollege.edu/~manderson/calendar/The%20Jewish%20calendar.htm|access-date=2021-01-31|website=faculty1.coloradocollege.edu}} * {{Cite web|last=לוינגר|first=יעקב|date=|title=על הכרזת המולד בבתי הכנסת|url=https://www.daat.ac.il/daat/shabat/luach/loewinger-molad.pdf|archive-url=|archive-date=|access-date=|website=Daat|language=he}} * {{Cite web|title=הלוח העברי - פרק ראשון: החודש|url=https://www.daat.ac.il/daat/shabat/luach/1a-2.htm|access-date=2021-01-31|website=www.daat.ac.il}}
Category:Hebrew calendar Category:Units of time
{{Unit-measurement-stub}} {{time-stub}}