A check (American English) or cheque (British English) is a bill of exchange made out to a payee and not, like paper money, a promissory note authorising any bearer.
It is a negotiable instrument and gives instruction to a financial institution to make a monetary transfer into the transactional account of either a person or an entity.
The date is the date of issue and the instrument is valid, usually, for a period of six months from the date of issue.
Under the heading 'Parts of a Cheque' the article documents the history of the instrument :
An issue date was added, and cheques may not be valid a certain amount of time after issue. In the US and Canada a cheque is typically valid for six months after the date of issue, after which it is a stale-dated cheque, but this depends on where the cheque is drawn; in Australia this is typically fifteen months. A cheque that has an issue date in the future, a post-dated cheque, may not be able to be presented until that date has passed, writing a post dated cheque may simply be ignored or is illegal in some countries.