On or before the 16th day of each month, each handler shall make full payment to the market administrator of the debit balance, if any, of such handler shown on the last statement of account rendered pursuant to section 20.71 of this Part. Payments to the market administrator shall be deemed not to have been made until such payments have been received by the market administrator. If the date by which such payments must be received by the market administrator falls on a Saturday or Sunday or a national holiday, such payments shall not be due until the next day that the market administrator's office is open for public business.