Delay this article by some time.
DELAY is a string, giving the length of the time.  Possible values are:
* 
  weeks (`w'), months (`M'), or years (`Y');
* YYYY-MM-DD for a specific date.  The time of day is given by the
  variable `gnus-delay-default-hour', minute and second are zero.
* hh:mm for a specific time.  Use 24h format.  If it is later than this
  time, then the deadline is tomorrow, else today.
(fn DELAY)