The fast breaks at sunset, and sunset shifts by a minute or so each day, so the time that applied last week is not the time tonight. If 8:19 pm is this evening's figure, this page counts down to it exactly — hours, minutes and seconds — which is what everyone in the kitchen actually wants to know.
There is nothing to start and nothing to choose. The page reads the clock on your device, works out the gap to 8:19 pm, and redraws it every second for as long as it is open. Leave it in a background tab if you like; the number will be current whenever you look back at it.
India runs half an hour off the round numbers, thirty minutes ahead of the Emirates, which catches out anyone arranging a call by counting whole hours. Since the clocks here never shift, the offset to Mumbai is fixed all year — it is the European and American ones that move underneath you.
Common questions
What is 20:19 on a 12-hour clock?
The same instant is 8:19 pm in writing and nineteen minutes past eight in the evening out loud. Anything from 13:00 onwards loses twelve to give the pm figure, which is the only sum involved in moving between the two.
Does the number update by itself?
Yes. It is recalculated every second from your device's clock, so nothing needs refreshing or restarting. Whatever is on screen is the current gap to 8:19 pm, not a figure worked out when the page first opened.
What happens once 8:19 pm has passed for today?
The count rolls over and carries on towards the same time tomorrow. That happens on its own at the moment the time passes — the page does not need reloading and there is nothing to reset by hand.
Which clock does the countdown use?
Your own. It reads the local time and time zone from the device in front of you, which in the Emirates means Gulf Standard Time, UTC+4. Travel and the count follows whatever the device picks up.