That is not a small number

When the Gregorian calender was introduced in 1582, authorities had to eliminate ten days, including October 13, to properly synchronize it with the seasons. Alas, October 13 did exist in 1981, and humanity is the poorer for it.

Yes, today is my birthday, and though I've provided you with the simple math involved, I'd prefer not to think about how long I've been around.

And now, a song!