A more thorough explanation:

A postdated check is a check that is written with a future date. This means that the check cannot be cashed or deposited until the date written on the check. It is like a promise to pay at a later date.

For example, if someone writes a check on January 1st, but dates it for January 15th, the check cannot be cashed or deposited until January 15th. This is because the check is postdated.

Postdated checks are legal, but they can be risky. If the person who wrote the check does not have enough money in their account on the date the check is cashed, the check will bounce and the recipient will not get their money.

Another example of a postdated check is when a person pays rent. They may write a check for the rent amount, but date it for the day after their paycheck is deposited. This ensures that the check will not bounce because there will be enough money in their account.