Snoop Dogg Is Today 4/20???

4/20/2011 6:32 PM PDT

Snoop Dogg -- Is Today 4/20???

Legendary weed advocate Snoop Dogg woke up this morning and posted this photo on his Twitter page today ... think he knows it's 4/20???

In case you missed it -- today, 4/20, is an unofficial stoner holiday. 

In fact, TMZ just spoke with Tommy Chong -- who told us he plans to celebrate by taking 420 hits from one of his favorite pipes at 4:20 PM. (Side note -- that can't be good for you.)

So, in summary, 4/20 seems like every other day for these guys.