When you are creating your cycle of training you will select a number of weeks that you want the training cycle to last for. The last week will be dedicated to the deload week. If you find that during the cycle you need to deload early or wish to push the training a little longer before deloading, you have the ability to do so. Simply hit the calendar icon at the top of the screen.
Once you hit the calendar icon you can hit the "+" or "-" to add or subtract from the number of weeks you want.