Info Catalog org: Relative timer org: Dates and Times

org: Countdown timer

 
 8.7 Countdown timer
 ===================
 
 Calling ‘org-timer-set-timer’ from an Org mode buffer runs a countdown
 timer.  Use ‘;’ from agenda buffers, <C-c C-x ;> everywhere else.
 
    ‘org-timer-set-timer’ prompts the user for a duration and displays a
 countdown timer in the modeline.  ‘org-timer-default-timer’ sets the
 default countdown value.  Giving a prefix numeric argument overrides
 this default value.
 

Info Catalog org: Relative timer org: Dates and Times