Why amateurs use UTC
Coordinated Universal Time (UTC) is the same everywhere and never changes for daylight saving, so a contact logged at 1430 UTC means the same moment to both stations, wherever they are. Logs, QSL cards, contest rules, net times and satellite pass predictions all use it. In the UK, UTC is the same as GMT in winter and one hour behind British Summer Time.
Tips
- Keep a clock in the shack set to UTC, so you don't have to work it out each time.
- Remember that the date changes at midnight UTC, which in the US happens during the afternoon or evening.
- Daylight saving starts and ends on different dates in Europe, the US and Australia, so the gap between local times changes for a few weeks each spring and autumn. The world clock table handles that.
The contest calendar shows contest times in UTC or your own time, and the grey line map has a live UTC clock with day and night across the world. For FT8, check your clock's accuracy with the FT8 clock check.
Questions
Is UTC the same as GMT?
For everyday use, yes. UK winter time (GMT) equals UTC, and British Summer Time is UTC plus one hour.
What time is 1800 UTC in New York?
2pm in summer (EDT, UTC−4) and 1pm in winter (EST, UTC−5).
Why does ham radio use UTC?
So that logs and schedules mean the same moment everywhere, without confusion over time zones and daylight saving.
Does UTC change for daylight saving?
No. UTC is the same all year, and local clocks move relative to it.