I don't know how I didn't know about this as I love math. Thanks to Aaron for alerting everyone! I am going to start planning a party for 4/4/16 tomorrow!
According to Wikipedia, a square root day occurs anytime "the day and the month are both the square root of the last two digits in the current year."
Today is the last square root day until 4/4/16. Celebrate now while you have the chance!