An agreement of purchase and sale for an industrial building is accepted conditional on financing...

The buyer can use the same amendment to ask for a change of the closing date.

The buyer can still waive the condition before the expiry date if the seller refuses to sign the amendment, provided there is a waiver provision in the condition.

The salesperson should prepare the amendment with midnight, May 17 as the irrevocable time.

To play it safe, the salesperson should amend the condition with May 18 as the expiry date.