When blondes do puzzles

A bunch of blondes walk into a restaurant celebrating and chanting "28 days, 28 days, it only took us 28 days!!"

Everyone was wondering what took them 28 days and why they were celebrating. Finally, when the blondes were about to leave, a waitor goes up and asks "What took you 28 days, why are you celebrating??"

All the blondes say "We just finished a puzzle in 28 days and on the box it said 3-6 years!!!"