Used to say to your homies that
1. it's time for an event to go down
2. it's time to start something that was planned
3. it's time to leave for somewhere that was planned

Origin: Might have originated from the saying 'Make hay when the sun shines'
Ron: I started up the Xbox. You do the first song. Did you get the beers?
Jake: Yeah man! It's hay time!
by Pseudonym, obviously January 2, 2009
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