868
xkcd #2897: Light Leap Years
(imgs.xkcd.com)
Alt text:
When Pope Gregory XIII briefly shortened the light-year in 1582, it led to navigational chaos and the loss of several Papal starships.
It falls often into sensible chuckle territory rather than stand-up comic material kind of funny.
Interesting you chose verbal delivery as being superior to drawn humor.
I didn't make a judgement on either.