Minn. Stat. § 504B.116: PRORATED RENT REQUIRED.

(a) When a lease term for a residential unit ends on a date before the last day of the final month, the amount of rent to be paid for the final month owed for the final month of rent must be prorated at the average daily rate for that month so that the tenant only pays for the actual number of days that occupancy is allowed. This provision applies to all leases, including leases requiring the last month of rent to be paid in advance. Any attempted waiver of this section by a landlord and tenant, by contract or otherwise, shall be void and unenforceable.

(b) For purposes of this section, prorated rent must be calculated using the actual number of calendar days for the calendar month in which the lease expires.