Buying and who gets the rent?

[Mike McCarthy]

Working on negotiating/buying a 3 unit MFP with 3 tenants in place.  How is 'first month' rent treated with a purchase?

If we close May 31st, do I get the June rent?  If we close June 1st, should I use the "extra" $$ that the seller gets as a negotiating tactic?  Or is it part of the settlement?  Or do most people not get concerned with one month rent?

Any suggestions how to handle?