24/07 is 4/20's big brother...
On every hour on the dot you must. smoke. weed.
A bong, a toke of a joint any way to inhale that smoke.
You must do this on for example: 00:00am, 3:00am, 12:00pm, 22:00pm...etc (all the other 24 hours in the day)
"Oh dude are you participating in 24/07 this year?"
"Nope, I always end up spewing everywhere."