Frequently asked questions

When the page loads it compares your device clock with our server clock and corrects for the difference and network delay. The result is typically accurate to well under a second, which is far finer than any mechanical watch can be set by hand.

Pull the crown out to the time-setting position (on many watches this stops the seconds hand, called "hacking"). Set the hands a minute ahead, wait until the second hand on screen reaches 12, then push the crown in.

Your device time zone is detected automatically. You can choose another zone from the picker above the clock, and your choice is remembered on this device.

We use the mean synodic month of about 29.53 days, counted from a known new moon. Most moon phase watches use a similar approximation, so the result matches what your dial should show to within a day.

Pick a Home and an Away location and the Travel Buddy shows how to set a GMT watch: where the local hour hand goes, where the GMT hand points, and how to turn the bezel. It works for both 24-hour and 12-hour bezels.

Yes. Tap "Quick access" in the header and follow the steps to add Set My Watch to your home screen on iPhone or Android. It opens full screen with a simple tab bar.

Once saved, the app shell and guides load offline. The clock still runs from your device time, but the server sync that guarantees accuracy needs a connection.

No accounts and no personal data. Your time zone, theme and Travel Buddy choices are stored only in your browser. See the legal page for details.