An informal notice of the date of an important upcoming event, usually a wedding, sent before a formal invitation.

plural of due date

(UK) The date on which something runs out or expires and becomes out of date, in many cases needing renewal.

A date by which an object either should not be used or loses its value, depending upon the item.

plural of sell-by date

plural of expiry date

(Canada, US) Synonym of best before date

(informal) The date on which a company (especially a startup) runs out of money or is expected to run out of money.

plural of date with destiny

synonym of International Date Line