A post-dated cheque is a cheque, on which a future date appears and not a current date.
For example, if today is 01/01/2012, then a cheque which bears a date (say) 15/01/2012 is a post-dated cheque, till that date (15/01/2012) comes.
In India, a cheque should be presented for payment on or after the date that appears on the face of the cheque. A banker cannot a pay a post-dated cheque as he has no mandate to debit the account of the depositor earlier than the date of the cheque. The bank can cash it unless it believes the check won't clear or is fraudulent.But they may be referring to the fact that you're not supposed to give someone a check that you know is not good at that moment. I'm working with the bank to see if they can't give you more of a break this one time. You will get burned, and you will be the one in the wrong.It will only become cheque on the date shown on it and prior to that it remains a bill of exchange under Section 5 of the Act.As a bill of exchange a post-dated cheque remains negotiable but it will not become a "cheque" till the date when it becomes "payable on demand".
In Serbia post-dating cheques is a customary practice in the retail industry.