A+/- and D+/- are target timing formats used to define when a task should start and/or finish relative to the flight's Arrival (A) or Departure (D).
Common formats:
A+ X: X minutes after arrival (example: A+ 5 = 5 minutes after arrival)
D- X: X minutes before departure (example: D-01:00 = 1 hour before departure)
Additionally, A and D indicate which movement the task is linked to, affecting which tasks appear for a flight:
If the flight is arrival-only, only tasks with A targets (for example, A+, A-) appear.
If the flight is departure-only, only tasks with D targets (for example, D-, D+) appear.