The last train back is the one time in an evening that genuinely will not wait, and working backwards from it is how people end up leaving earlier than they meant to. If 7:16 pm is that departure, the countdown here gives the exact figure rather than a comfortable guess.
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 7:16 pm as it stands at that moment.
Writing a time as 7:16 pm keeps the am or pm attached, which reads naturally in a sentence but is easy to skim past in a long list of similar entries. Writing it as 19:16 is less conversational and considerably harder to misread, which is why schedules and rotas lean that way.
Common questions
What is 19:16 in the 12-hour clock?
That is 7:16 pm, or sixteen minutes past seven in the evening if you are saying it aloud. From 13:00 onwards, subtracting twelve gives the pm figure — the same moment written three different ways.
Does the number update by itself?
Yes. It recalculates every second from your device's clock, so there is nothing to refresh or restart. Whatever is on screen is the current gap to the target time, not a figure worked out when the page first loaded.
What happens if 7:16 pm has already gone for today?
The count simply carries on towards the next occurrence, which is tomorrow. That rollover happens on its own — the page does not need reloading and there is nothing to reset by hand.
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.