How fast time has passed by!

The cast and crew of ABC Family's hit show 'Pretty Little Liars' celebrated production on the show's 100th episode Saturday night. Among those in attendance included stars Sasha Pieterse, Lucy Hale, Ashley Benson, Keegan Allen, Shay Mitchell and Troian Bellisario.

Not only is 100 episodes a special feat since most television shows don't last that long, but 100 shows is the targeted benchmark for any TV series in production since it usually opens the door for syndication opportunities. In other words, you might be catching 'Pretty Little Liars' reruns soon on channels other than ABC Family.

Keegan Allen took to Instagram to post a picture of the cast and crew slicing a giant cake marking the occasion. The cake has the text "Celebrating 100 Episodes B----s" along with a letter 'A' at the top.

'Pretty Little Liars' is based on the young adult novel series by Sara Shepard and concluded its fourth season on March 18. Season five will debut on June 10.