READY
READY
Fifteen seconds is the length of a short answer. It is the standard slot for the shortest broadcast advert, roughly what a social clip gets before a thumb moves, and about as long as anyone will listen to an explanation they did not ask for.
It does honest physical work too: the rest between heavy sprint repeats, a hold at the end of a stretch, and the time hand sanitiser needs to be rubbed in before it has done anything at all.
The tip is for anyone who has to speak. Practise the fifteen second version of your answer before the long one: set this running and say the whole point out loud. If you cannot finish, the answer is not too long, it is not decided yet, and no amount of extra time fixes that.
Start with the button or the space bar. Tap the readout and type a different number if fifteen turns out to be the wrong slot.
Mostly rehearsal and rest. It is the length of a short ad, the gap between hard sprint repeats, and a useful limit to practise a spoken answer against.
For rehearsing to length, yes. For editing, no: your recording software already knows the exact duration, and a browser timer cannot be more precise than that.
The countdown does, because the end is stored as a real clock time. Whether the sound reaches you depends on the phone, so for anything you must not miss, keep the screen on.