Wednesday is the pivot of the British week, and it holds one fixture that belongs to no other day: Prime Minister's Questions, held at midday in the Commons on every sitting Wednesday. Around that sits an entire midweek routine — the football played on Wednesday evenings since floodlights arrived, half-day closing still surviving in a handful of market towns, and the weekly meeting nobody ever schedules any later.
In schools it tends to be the heaviest day on the timetable, and for anyone working a standard week it is the point at which the days already worked outnumber the days still to come. That turn is real enough that "hump day" has crossed the Atlantic and stuck, even though the phrase has never sounded remotely British.
The countdown here is a short one by definition. Because Wednesday sits in the middle of the week it is rarely more than a few days off, and the figure is measured to the second rather than rounded — which matters when what you are actually waiting on is a delivery slot, a results release or a kick-off rather than the day in the abstract.
It targets the midnight at which the next Wednesday begins, so a countdown checked on a Wednesday afternoon is pointing at the one a week ahead rather than at the hours left in today.
Common questions
What happens at midday on a Wednesday in Parliament?
Prime Minister's Questions, held for half an hour whenever the Commons is sitting — the one fixed weekly event in the parliamentary diary.
How long can this countdown be?
Just under seven days. It always targets the nearest Wednesday, so it can never show more than a week.