A meeting booked for just after lunch is the one most likely to catch someone out, because the morning overruns and nothing interrupts the drift. This page counts down to 11:34 am exactly, updating continuously, which is more reliable than a mental note to check back in a bit.
The count makes no sound and asks for no attention while it runs. It is a number, not an alarm, and nothing goes off when it reaches zero. Leaving the page open in a background tab is perfectly fine — it will carry on counting towards 11:34 am whether or not anyone is watching it.
Plenty of phones, laptops and dashboards default to a 24-hour display regardless of how people around here actually talk, so 11:34 may well be the figure staring back at you even though 11:34 am is how the same moment would be said aloud. Neither is more correct than the other.
Common questions
What happens if 11:34 am 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.
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 11:34 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.