Broadcast Clock v12.0 ✨

What a broadcast clock is

A broadcast clock — also called an hour wheel or a format clock — is the map of a single hour of radio. It says what goes where: when the news comes, how long the music sweep runs, where the commercial breaks sit, when the presenter talks over the intro, and where the hour hands over to the next one.

It is drawn as a circle divided into segments, because an hour of radio is a cycle that repeats. Once a station has agreed its clock, every hour of that daypart has the same shape, and listeners learn it without ever being told.

Why stations use one

• Consistency. A listener who tunes in at ten past knows the news is at the top of the hour, every hour.
• Commercial planning. Advertisers buy positions. A fixed clock is what makes those positions sellable.
• Handover. Networked programming only works if every station reaches the junction at the same second.
• Discipline. The clock is what stops a good conversation from eating the traffic bulletin.

The usual building blocks of an hour

• Top of hour. News, station identification, time check.
• Music sweep. Two to four tracks without interruption, to establish flow.
• Talk break. Presenter content, kept short and placed where the audience is largest.
• Commercial break. Usually at :20 and :50, so that it can be sold as a fixed position.
• Traffic, weather or sport. Anchored to the same minute every hour so people can plan around it.
• Promo or trailer. Driving the audience to the next programme.
• Junction. The exact second when the hour ends. Everything else is negotiable; this is not.

How to build one with this tool

1. Start from the fixed points: the junction, the news, the commercial breaks. They are contractual and cannot move.
2. Fill in the music and speech segments around them with realistic durations — not the durations you wish they had.
3. Check the total. An hour that adds up to 61 minutes is an hour that will crash into the news every single time.
4. Build a different clock for each daypart. Breakfast, daytime and drive have different audiences and different rhythms.
5. Save it, print it, and put it where the presenter can see it.

The clock on the wall and the clock on the page

A format clock only works if everybody agrees on what time it is. In a station with several studios, a newsroom and a network feed, that agreement has to come from somewhere: a single reference distributed to every display, every automation system and every recorder.

That is the other kind of broadcast clock, and it is the one we make.