The written contract (hopefully your boyfriend has a written contract) would govern payment terms. If the written contract has no specified time period for payment, then any "reasonable" time may apply.
It's not at all unusual for contracts to give someone who owes money for services weeks, and even months, to make payment.
Of course, as with all of my online answers, my advice is limited by the brevity of your question and the facts provided. Additional information would be required to provide definitive legal advice, so this answer isn't intended to, and does not, create an attorney-client relationship.
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