ECONOMY rental desk at Ontario International AirportOntario International Airport is open at the following times: , Monday from 07:00 until 21:59, Tuesday from 07:00 until 21:59, Wednesday from 07:00 until 21:59, Thursday from 07:00 until 21:59, Friday from 07:00 until 21:59, Saturday from 07:00 until 21:59, Sunday from 08:00 until 17:59