Friday this week is an Addition Day:  06 + 07 = 13.

Every month this century has had one Addition Day where the Month + Day = Year.  (This uses the definition that the first year of the century was 2001, since there was no year zero).  Addition days will stop at some point.  We will name that point in a later post.  Don’t worry, it won’t happen for a while!

I like to think of Thursday, 6/6, as Gravity Day. The gravitational constant G ~  6.672 x 10^11.  I made up Gravity Day.  Fortunately for all of us, I did not have to make up G; it was already there.