Most of Arizona does not observe daylight saving time, so polls close at 7pm Mountain Standard time (10 pm Eastern Daylight time). The exception is Navajo County. Polls there close at 7pm Mountain Daylight time (9 pm Eastern Daylight time).
Arizona is a closed primary state. There are 58 delegates up for grabs and is winner take all for Republicans. There 75 delegates, awarded proportionally, for the Democrats.