Why does my watch face show -- instead of a number?

The faces on this site follow one rule: if the watch has no value for something, the face shows -- instead of a number. A made-up number would be worse than an honest gap. When you see --, the watch did not hand over that value. The usual reasons:

• Your watch does not measure it. Floors need a barometric altimeter; some values, like Body Battery or power, exist only on some models. Each face's page lists the watches it runs on, but a value can still be missing on one of them.
• There is no data yet today. Just after midnight, or right after you put the watch on, steps and heart rate can be empty for a moment.
• The sensor is off. If wrist heart rate is turned off, heart rate shows --.
• The phone has not synced. Weather comes from the phone. Without a recent sync, temperature and forecast stay empty.
• Sunrise and sunset need your position. See why sunrise and sunset show --:--.

If a value stays at -- although your watch shows it elsewhere, write to the support address on the face's store page: it helps fix the face for everyone.