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At any camp or sleepover involving junior high boys, the time after "lights out" to begin making farting noises, real or imitated.
The youth director is asleep - it's fart thirty!

(sleepy camper) What time is it?
(friend rips one)
(sleepy camper) Oh. It must be fart thirty! (responding in kind)
by bob beeflips November 16, 2011
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