A check that becomes payable and negotiable on a future date specified.
A check dated for one or more days after it is written. For example, if one dates a check for January 31st, and it is currently January 25th, it is a postdated check. Theoretically, banks do not honor postdated checks, though many do anyway.
Once you've chosen your future home and your bank, the next step is to make the downpayment to your developer, usually through post dated checks. If you've chosen a pre-selling project, then you get to wait and anticipate excitedly for a few more years.