For mortgage applications, the term “business day” is used in setting the period of time lenders have to return 2 key forms that document the loan status. The definition is NOT consistent, though!
Loan Estimates, which are a required response for approved loans, are due back to the applicant within 3 business days. In this case, “business day” is every day on which a financial institution’s workplaces are open to the general public. If a particular lender is always closed on Thursday, their deadline might be different from that of another lender.
Closing Disclosures must be supplied 3 days prior to consummation of the loan, but in this case, “business day” is defined on a common calendar: all calendar days except Federal public holidays, plus Sundays. In short, all lenders work from the same calendar for Closing Disclosures.