If a closing disclosure is sent to the borrower electronically (in accordance with E-Sign) on Monday before the end of the creditor’s business hours, but the borrower does not acknowledge receipt of the closing disclosure until after business hours on Monday, can the creditor consider it received on Monday? Or are we required to use Tuesday as the receipt date because it was acknowledged after business hours?

There is no guidance - but Monday is still Monday.

Agreed. For this purpose, each day has 24 hours, whether you are open or not.

Thank you!