our school (private) goes (k) 8-12:30 m-th/ 8-12 f
(1st -8th) 8-3 m-th/8-12 f
but they only get 30 minutes for lunch break, 1 day off for non federal holidays, start in early august and get out in june. more parents want full day kindergarten so they may change it next year.
the public schools in my neighborhood go shorter hours (i think 1st-6th is 8:15-2:45 and out at noon on wednesdays), go less days-just the bare minimum number that is required by law.
i remember going to kindergarten from 8-11:30 (the afternoon kids went from 12-3:30), elementary being 8-3:30 (but we got an hour for lunch and 2 25 minute recesses) jr and senior high 7:50-3:10.
i can't imagine how a kindergarten teacher manages to accomplish much with 4 hours or less-between getting them settled down, potty breaks, snack, recess, getting them together to leave...i think it's harder for little ones to go the full day, but tons more go to preschool or daycare and are used to being dropped off at 7 & picked up at 6 so it may seem the norm for them.