Molad based on a constant interval cycle that is widely but incorrectly regarded as an approximation of the time in Jerusalem of the mean lunar conjunction. Each "molad" moment occurs exactly 29 days 12 hours 44 minutes and 3+/ seconds (or, equivalently, 29 days 12 hours and 44+/ minutes) after the previous "molad" moment. This interval is numerically exactly the same as the length of the mean synodic month that was published by Ptolemy in the Almagest, who cited Hipparchus as its source. Although in the era of Hipparchus (2nd century BC) this interval was equal to the average time between
April 2015 lunar eclipse 17 October 1529 (which lasted 1 minute and 42 seconds). Another shortest occurs on December 28 1917, lasting (11 minutes and 58 seconds). The next very short lunar totality will occur on 26 May 2021 (which will last 14 minutes and 24 seconds). This was the sixth total lunar eclipse out of nine with totality under 5 minutes in a five millennium period between 2,000 BC and 3,000 AD. However, due to the oblateness of the Earth, this lunar eclipse may have actually been (barely) a partial eclipse. This eclipsed moon was 12.9% smaller in apparent diameter than the supermoon