Our local kids rec league plays running clock for 3rd & 4th grade, six minute stop time quarters for 5th & 6th and seven minute stop time for 7th & 8th. Halftimes are three minutes. There are no OTs at 3rd & 4th and only two minute OTs at the other levels (and only one OT). The officials have the authority to not play OTs if the games are running behind. If the game ends in a tie, so be it.
Of course, I never allow OTs anyway, so that point is moot.