We can take a pretty educated guess at how some celebrities will spending this weekend.

Tomorrow is 4/20, otherwise known as the international day to smoke up. And in the land of Hollywood, where medical marijuana cards are as commonplace as drivers licenses, it's safe to say that plenty of celebrities will be, umm, "celebrating." Not only that, but these A-listers are pretty open about their love of Mary Jane, going on the record in interviews as avid pot fiends.

Check out our roundup of the 20 "greenest" celebs who will definitely be celebrating 4/20!

One of Demi Lovato’s more recent singles was “Give Your Heart A Break,” but it was Demi’s leg that was given a break more recently ― as the girl behind (the now ironically titled) Unbroken revealed on last night’s Jimmy Kimmel appearance. And she holds a certain Oscar-winning actress from this year responsible!

(No, it’s not Anne Hathaway… though we kind of wish it was Anne Hathaway.)

In addition to blaming Jennifer Lawrence for all her ills, Demi performed “Heart Attack,” dished on returning to The X Factor, and narrowly avoided a Khloe Kardashian diss. Catch it all after the jump!

You probably didn’t know it, but it’s music’s birthday this week!

"Music?" you ask. "But which genre of music? Which artist?"

The answer is simple: all genres! All artists!

Okay, maybe not all of them. That’s an exaggeration. But this last week of March has a curiously high number of birthdays for some seriously legendary musicians, including old pros and newer artists who have made their mark, representing genres across the board. So, in honor of such huge talent, we are declaring this week Music’s Birthday.

Join us in celebrating after the jump, won’t you?