A task deadline may be set, changed and deleted again using 
 Change  
  Deadline  
or  File  
  Change  
  Deadline  
in the task view. When filling in the deadline date fields, use YYYY-MM-DD date 
format. Entering a void date field deletes the deadline if present. Changing the 
task deadline is possible unless the task has reached a final status 
(accepted or cancelled). When the deadline has passed and the task 
has not been finished, the deadline is displayed in red in the task view.
  Change  
  Deadline  
or  File  
  Change  
  Deadline  
in the task view. When filling in the deadline date fields, use YYYY-MM-DD date 
format. Entering a void date field deletes the deadline if present. Changing the 
task deadline is possible unless the task has reached a final status 
(accepted or cancelled). When the deadline has passed and the task 
has not been finished, the deadline is displayed in red in the task view.