A group of blonds walk into a bar. One of the women tells the bartender
to line up a row of drinks for all of them. The gals lift their glasses
and toast, "Here's to 51 days!" and they proceed to down the their drinks.

Once again, they tell the bartender to "line 'em up!", and once again they
toast to 51 days and down their drinks..

The bartender says, "I don't get it. Why in the world are you toasting
51 days?"

One of the blonds explains, "We just finished a jigsaw puzzle that had
'2-4 years' written on the box, and we finished it in just 51 days!"