Sydney Airport Demand Management Act 1997

A *gate movement on a day is an off‑slot movement for that day if:

a slot permitting the movement on the day on which it occurs has been allocated under the *Slot Management Scheme; but

either of the following applies:

for a flight with a *block time of less than 3 hours—the movement occurs more than 15 minutes before or after the time specified for the movement by the slot;

for a flight with a block time of 3 hours or more—the movement occurs more than 30 minutes before or after the time specified for the movement by the slot.

The regulations may prescribe circumstances in which a *gate movement is an off‑slot movement.