Here is a note on the widely used civil calendar in the world – the Gregorian Calendar. No child was born from 5th Oct 1582 to 14th Oct 1582 on the Gregorian Calendar! This was because, the Gregorian calendar was the refined Julian Calendar (that was in use prior to the Papal Bull, a sort of an ordinance by the Pope on Feb 24, 1582, which almost all Europe obeyed). In order to deal with a ten-day accumulated drift that occurred due to the shortening of the Gregorian day to the Julian day by 648 seconds or 10.80 minutes per day, it was necessary to advance the date so that 4th October 1582 (a Julian Thursday) was followed by 15th October 1582 (a Gregorian Friday). There was no discontinuity in the cycle of weekdays in the Gregorian calendar – only the dates were advanced and not the respective days.