24-Hour Solar Clock · iOS · Free with Sol Pro
Sol Clock shows you where the sun actually is in the sky at every moment of the day. One full rotation of the hand equals one solar day, anchored to solar noon — not the arbitrary midnight of the modern clock.
The St. Mark's face is inspired by the great astronomical clocks of Venice and Prague: a 24-hour dial with a zodiac ring, a live sky color temperature ring, and an earth at the center showing day and night in real time.
No account required. No advertising. No data collection. Your location is used only on-device for solar calculations and is never transmitted or stored.
If you're interested in canonical hours, the Roman liturgical calendar, and Catholic prayer times, check out Ave Maria Clock — the full version of the same app.
Ave Maria Clock →Unlock the Sky Map, Sun & Moon Compass, and unlimited solar alarms with a Sol Pro subscription. Includes a 7-day free trial.
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Why does the hand point down at noon?
Solar noon is pinned to 12 o'clock at the top of the dial. Because the hand starts at noon and completes one full rotation over the solar day, it points straight down at midnight — matching how ancient astronomical clocks were read.
What does the color ring around the orbital band mean?
The orbital ring — the band the sun's ball travels along — is a full 24-hour color wheel. Each segment shows the actual sky color for that time of day based on the sun's altitude: deep indigo and violet through the night hours, warm orange-gold at sunrise and sunset, soft yellow-white in the morning and afternoon, neutral pale blue at midday. The colors are computed from today's actual sunrise and sunset at your location and shift subtly with the seasons.
What does the color temperature readout mean?
The readout below the clock shows the correlated color temperature (CCT) in Kelvin and the current light phase. Lower CCT (2,500–3,500 K) means warm amber light — golden hour. Higher CCT (5,500–6,500 K) means neutral white light — midday. This tells you the quality of sunlight available at any moment.
What is the sky gradient behind the clock?
The background color reflects the current sky conditions based on the sun's altitude at your location. It cross-fades smoothly throughout the day — deep violet before dawn, warm peach at sunrise, pale blue at midday, orange-gold at sunset, dark indigo at night.
What is the Morning Light alarm?
Morning Light fires approximately 15 minutes after golden hour ends — when the sun's altitude reaches about +10°. Research suggests this window (roughly 10°–30° above the horizon) provides the most beneficial light spectrum for circadian rhythm entrainment. The exact time shifts daily with your latitude and the season.
What is the Afternoon Light alarm?
Afternoon Light fires approximately 15 minutes before evening golden hour begins — when the sun is still above +10° but descending toward the warm light of dusk. It marks the end of the optimal afternoon light window before the color temperature drops into golden hour.
Why do my alarms fire at slightly different times each day?
All solar alarms are computed from the actual astronomical position of the sun for your location on that calendar date. Solar noon, sunrise, and sunset shift throughout the year, so the alarms follow the sun, not the clock.
What is solar time and how is it different from standard time?
True solar time tracks the actual position of the sun in the sky. Solar noon — when the sun is at its highest — is 12:00 in solar time, but may be anywhere from 11:30 to 12:30 in standard time depending on your position within your time zone. Sol Clock displays both so you can see the difference.
Why does the app need my location?
Sunrise, sunset, solar noon, and all other solar events are different for every point on earth and change every day. Your location is required to calculate them precisely. It is never transmitted to any server — all calculations happen on-device.
What if I deny location access?
You can enter a city name or zip code manually. Sol Clock will use that location for all solar calculations until you update it.
Sol Clock does not collect or share your personal data. Your location is used only on-device to calculate solar times. It is never transmitted to any server, stored remotely, or shared with third parties. The app has no analytics, no advertising, and no account system.
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