How long until 9:00 pm?

Nine in the evening is the watershed in British broadcasting — the point before which television scheduled for a general audience must avoid material unsuitable for children, and after which the tone of the schedule changes noticeably. It is one of the few regulatory rules the public actually knows by heart.

It is also the hour at which the day starts closing down. Smaller shops have long shut, last orders for kitchens in most pubs fall around now, and the final post-work commitments finish. In midsummer the sun has only just gone down in the south of England and is still setting in Scotland; in winter it has been dark for five hours.

People counting towards 9 pm are usually timing a programme, a call, or the end of an evening obligation. The wait shown recalculates continuously and never exceeds twenty-four hours.