The Tube at this hour is a matter of joining the right crowd rather than choosing a seat, and getting through it depends on leaving at a specific minute. This page counts down to 9:46 am precisely — the moment to leave, the moment to touch in, or the moment a meeting on the other side begins.
Coming back to this page in an hour, tomorrow or next month shows exactly the same thing: however long is genuinely left until 9:46 am next comes round. There is no session to lose and nothing to configure again, because the number is worked out fresh each time from the clock on your device.
Between the last Sunday in March and the last Sunday in October the country runs on BST rather than GMT, which is why timetables and confirmations sometimes carry the label as well as the number. This page counts down to 9:46 am using whatever your device is currently set to, so the switch is handled for you.
Common questions
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 09:46 in the 12-hour clock?
That is 9:46 am, or fourteen minutes to ten 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.
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 9:46 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.