scd / setcountdown            Sets a countdown
 
   Format:
      ;scd                    Starts the Countdown task
      ;scd <num>              Counts down <num> seconds
      ;scd -s <num>           Counts down <num> seconds
      ;scd -m <num>           Counts down <num> minutes
      ;scd -h <num>           Counts down <num> hours
      
   Notes:
      This commands starts the Countdown task, or uses an existing one (if one
         is running, and is not already counting down or up).
      The task counts down from some time that you specify. The arguments can
         occur in any order, so all of these are acceptable:

         ;scd 60
         ;scd -s 60
         ;scd 60 -s
         
      The maximum time allowed is 99, 59 minutes and 59 seconds. If you
         specify a longer time, the maximum is used instead.
      If you don't specify a time and no Countdown task is running, one is
         started. You can use the task window to start the clock as soon as
         you're ready.         
      See also the help for ';setcountup', which counts updwards from zero.

   User commands:
      scd / countdown / setcountdown
