Tell the landlords to shove it, unless their leases have some sort of clause where they can demand rent early whenever they feel like it.
I'm willing to bet the managers of this government funded complex were told to ask for rent payments early as a means of scaring the tenants.
What are they going to do if they can't pay early? Kick them out to make room for illegal aliens?
Given that this is Californistan, that may be a real possibility.