DayLength
Know your daylight
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
Know exactly when sunrise and sunset happen — any day, any place on Earth. Plan outdoor activities around available daylight.
Will it still be light when you finish work? Can you fit a run outside before sunset in December? DayLength answers these questions precisely, for any day of the year, anywhere on Earth.
Enter any geographic coordinates or search for a city. DayLength calculates sunrise, sunset, and total daylight duration for every day of the year using the NOAA solar calculation algorithm — the same method used in scientific and navigational systems. All computation happens on your device, instantly, with no network required.
HOW IT WORKS
Open the app and enter your location — type coordinates manually or search by city name. Tap Explore Daylight. An interactive annual chart appears, showing how day enght changes across every day of the year. Drag your finger across the chart to explore any date: the exact sunrise, sunset, and total daylight hours update in real time.
The app automatically detects polar phenomena — midnight sun and polar night — for high-latitude locations such as Reykjavik, Tromsø, or Anchorage.
KEY FEATURES
• Annual daylight chart with drag-to-explore interaction
• Precise sunrise and sunset times for any date
• Total daylight duration in hours and minutes
• Polar night and midnight sun detection for extreme latitudes
• City search powered by Apple Maps
• Manual coordinate input with quick presets
• Fully offline — all calculations run on-device, no internet required
• Day/Night progress bar
PRIVACY FIRST
No account. No sign-up. No tracking. No ads. No subscriptions.
Your coordinates are stored only on your device. City search uses Apple's MapKit framework. DayLength makes no network requests of its own.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
The developer, PIERO BOZZOLO, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- PIERO BOZZOLO
- Size
- 2.2 MB
- Category
- Weather
- Compatibility
Requires iOS 16.0 or later.
- iPhone
Requires iOS 16.0 or later. - Mac
Requires macOS 13.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
English and 6 more
- English, French, German, Italian, Portuguese, Romanian, Spanish
- Age Rating
4+
- 4+
- Copyright
- © Piero Bozzolo