the cheque will become stale in 3 months from the cheque date. Yes, you have to pay the creditor even if has not presented the cheque. But suggestion will be pay after the request from the creditor (without any interest)..
as per accounting concepts, if the issued cheques are not vitalising, and the cheques has gone stale then the Liability for unclaimed amount may be shown in the balance sheet. Moreover, as the per the Limitation Act, if any debt is not claimed within 3 yrs from the due date on which it is to paid, then the person shall not be liable to pay it after the said 3yrs. so in my view, you should book such profit after third yr.