#2248: New Year's Eve

XKCD comic, described below.
Transcript

[Cueball, with his hands raised, is talking to Megan and White Hat.]

Cueball: Tomorrow is New Year's Eve, and you know what that means:

Cueball: It's the one day of the year when you can convert between ages and birth years by subtraction without worrying about off-by-one errors!

Cueball: Also there are probably parties.


(Sourced from explainxkcd.com)

Title text:"Off-by-one errors" isn't the easiest theme to build a party around, but I've seen worse.


ExplainOriginal