A post-dated cheque is a cheque or note on which the drawer has written a date later than the date on which the cheque was written.
In many jurisdictions, banks will, if funds are available, pay immediately a cheque is presented by the payee, disregarding any future dating at the time of presentation, even if they notice it.
Accordingly a drawer who has post-dated a cheque as they lack cleared funds at the time of writing, expecting to receive them before the date written, is putting trust in the beneficiary not to deposit the cheque or present it for payment prior to the stated date.
Exact law and practice regarding post-dated cheques may vary between jurisdictions.
However, in some jurisdictions it is customary and contractually usual for some payments to be made using post-dated cheques that are provided to the beneficiary in batches. For example, in India it may be usual for tenants to provide cheques in batches of three each quarter to pay the coming three months' rent and the landlord will deposit them one at a time each month of that quarter.
There are variations between States in the United States - even though US Federal law also applies with additional procedural requirements and criminal offences.
Issuing a cheque with no intention of paying however, is likely to be a criminal offence (a type of fraud) in most jurisdictions.