This week has three dates whose month, day, and year are all multiples of three: 9/6/15, 9/9/15, and 9/12/15.

In addition (pun intended), 9/6 is an Addition day, since 9 + 6 = 15.

And the next (pun also intended) cool day is a Sequence of 3’s: 9/12/15.

Bonus fact: 9/9/15 is our anniversary. 43 years!