Options are the right to buy or sell these investment assets at a set price before a specified date in the future.

BBC: Hedging - a rough guide

Apple release their staff from having to deliver products by a specified date, rather they can deliver when the product is ready.

FORBES: Where Was Apple's Hardware Release For March?

Calls are option contracts that can give buyers an inexpensive bet that a stock will rise above a specified "strike price" before a specified date.

WSJ: Upside: Options for Nervous Investors

Also, in some cases, like Thailand, some of the new expenditure programs aimed at employment creation will end at a pre-specified date.

CNN: REFORM IS CRUCIAL

It means the host needs a definite head count for the planned event, and needs it by the date specified on the invitation.

FORBES: Importance of the RSVP