Submission deadlines are strict. There is no possibility to submit a problem sheet after its deadline has passed. It can be submitted as many times as you wish prior to the deadline - the final submission is the one that counts. To avoid last minute difficulties you should submit work a few days before the deadline.
A valid doctor's certificate or equivalent, covering the 72 hours prior to the deadline, is needed for an exemption on a problem sheet.
If there is any question please contact:
Your lecturer