A day has 24 hours and 1,440 minutes. Every one of them has a page here: what time it is in 24 cities, what it costs to own on the1440.com, and who has already aired in it.
Pick an hour to see its sixty minutes. All times are UTC, the clock the whole schedule runs on — the same as GMT, and the same as London in winter.
Prime minutes, 14:00–17:59 UTC, cost $5: the US morning and the European afternoon overlap. Peak minutes, 12:00–13:59 and 18:00–21:59, cost $3. Everything else is off-peak at $2. Full rate card and FAQ.