2017 Christmas On A Monday — First Time In 11-Years; Last In 2006.
Click to ENLARGE.
Leap Years marked in grey.
Last time we had Christmas, i.e., December 25th, on a Monday was in 2006 — 11-years ago.
That is unusual, but not extraordinary. We get a 11-year gap, every 4th time around. The cycle as to when the same date falls on a given day (e.g., Monday) goes in 1 6-5-6-11 cycle. You can see that in the last image above — as to when Christmas has fallen on a Monday. So, it was 1989, 1995, 2000, 2006 …. and then 2017.
This 6-5-6-11 cycle has all to do with leap years. You can see that in the 2nd figure above.
After 1995 it was but 5-years because we had TWO leap years, i.e., 1996 & 2000. In each case we LEAPT over a day (which is why we call it a Leap Year, i.e., because we leap over a day, in the calendar). Because of the two leap years, the gap was only 5-days. Then, between 2000 and 2006 there was only ONE leap year. So we only leapt over one-day. The gap was thus 6.
Now look at what happened in 2012, which was a leap year. That should have been the Monday, but we skipped over that. Hence, the 11-year gap. Neato. This 6-5-6-11 cycle is inescapable and applies to all calendar events, birthdays, holidays, whatever.
Some of you may claim “but, didn’t we have Christmas on a Monday last year (2016), in 2011 and in 2005?” NO, you didn’t! Christmas, on those years, fell on Sunday. So, Monday was made a holiday. Big difference. OK?