Delivery slots and tradespeople's arrival windows are given as a range but tend to hinge on a specific time, and waiting in for one eats a morning if you are not tracking it. This page counts down to 6:16 am exactly, which is a good deal steadier than checking a clock every few minutes.
Nothing is downloaded, nothing is registered, and nothing is left on the device afterwards. The whole count runs inside the page you already have open. Closing it costs nothing at all, and opening it again later simply shows the accurate gap to 6:16 am as it stands at that moment.
Twelve o'clock is where the 12-hour clock is at its weakest, since 12 am and 12 pm are read the wrong way round often enough to cause real trouble. Writing a time as 06:16 removes the problem outright, because a 24-hour figure only ever points at one moment in the day.
Common questions
Which clock does it use?
Your own. It reads the local time and time zone from the device you are looking at, so the figure reflects where you actually are rather than a fixed zone written into the page.
Will this alert me when the time arrives?
No. It is a live number rather than an alarm — nothing rings, buzzes or notifies you at zero. If you need to be interrupted at 6:16 am, set an alarm as well and treat this page as the running total.
Is it affected by the clocks changing?
Only in the sense that your device is. When the change between GMT and BST happens at the end of March and October, the device adjusts and the countdown follows it without anything to do here.
What is 06:16 in the 12-hour clock?
That is 6:16 am, or sixteen minutes past six in the morning if you are saying it aloud. From 13:00 onwards, subtracting twelve gives the pm figure — the same moment written three different ways.