Well fancy the illustrious Harvard University using Yale brand locks on its buildings. How ironic.
Generally speaking, 29th February occurs once every four years, because there aren’t precisely 365 days in a year but approximately 365 and a quarter.
That means it takes the earth 365 and a quarter days to go round the sun and complete an astronomical year.
This extra day every four years allows the man-made calendar to catch up with the astronomical calendar.
However, because it isn’t quite a quarter day that needs to be added, we only need leap days 97 years (not 100) out of 400.
It is for this reason that we have this formula. There’s a leap year every year that’s divisable by four unless that year is divisable by 100.
If it is divisable by 100, it would be a leap year if that year was also divisable by 400 (as 2000 was). So although 1900 was divisable by four, it wasn’t a lear year.
I wonder how many of you mathematical geniuses know that the number Forty is the only number that has all its letters in alphabetical order.
No it’s not a trick, take a look for yourself and go through the alphabet….
Now we bet you never new that!