If it were a "male only" hour, or a conservative Christian group, there would be screaming from the rooftops.
So they employ male and female lifeguards but kick out the male employees to accomadate the Muslims. This only makes the public pool party to the suppression of Muslim women by their jerk zip-wad men. Make them follow the pool rules and wear appropriate swimsuits.
Or....they could put their own swimming pools in their Islamic Centers that are so well financed with oil profits.