I had a free day with nothing else to do, so I went to see “Hot Tub Time Machine.” It completely lived up to my expectations by being exactly — not one bit more or less — as stupid as I thought it would be.

Like “Snakes On A Plane,” you know the entire premise from the title. The studio pitch session took about five seconds: there’s this hot tub, you see, that’s also a time machine and….okay, sold!

While not as good as “The Hangover,” “Hot Tub Time Machine” is in the same ballpark. It helps if you lived through the 80s or ever dated a woman who started wearing leg warmers after seeing “Flashdance.” As for the cast, Rob Corddry is so over-the-top outrageous that he must have ingested whatever stimulants Jack Black used to take. John Cusack does his usual solid job, Craig Robinson is funny, and Crispin Glover gets to work in another time-travel movie.

You don’t need to know anything else about the plot. You either buy it or your don’t buy it. I bought it.

Now the caveat: don’t see “HTTM” if you’re not a fan of stupid, crude, relentless, silly, sophomoric, or any synonym you like — they all apply.