Why Feb 17? Sabians worship the 17th day of every month, but in particular, the 17th Day of the 2nd Month; which on the Solar Calendar is Feb 17 corresponding to the date the Flood began (Gen 7:11); 7 the number of perfection; 11 the number of Antichrist. Sabians created the Solar (Gregorian) Calendar to match their Feast of Nativity with Christmas.