Top of the dial is solar noon: the sun at its highest where you are.
Bottom is solar midnight.
The marks round the rim are normal clock hours. The thick one near the top is 12.
The small dot on the rim is the minute. It starts at the 12.
The face
Day — sun above the horizon, from sunrise to sunset.
Civil twilight — sun 0° to 6° below the horizon. Bright enough to see by.
Nautical twilight — 6° to 12° below. Horizon still visible, brighter stars out.
Astronomical twilight — 12° to 18° below. Dark to the eye. Only instruments can tell it from night.
Night — sun more than 18° down. Stars, and the moon as it is tonight.
The short ticks inside the face: sunrise, sunset, solar noon, mid-morning,
mid-afternoon. Tap the clock to show or hide the time.
Time zone
Location
Tide
A faint band in from the rim. The deeper it reaches, the higher the water.
One hour-tick length is one metre above the lowest water of the past month.
Sun times come from sunrise-sunset.org. The tide, when
it is on, comes from the Open-Meteo marine model. Both are asked for your location and date only.
The moon phase is worked out on the phone.
This clock draws the sky for where you are. Use your location?