AbraCalc

Sun & Moon Today

See today's sunrise, sunset, day length, and moon phase for any location, drawn as a sun arc across the sky. Enter a city or use your location — all math runs offline.

Built by the AbraCalc team

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How to play

  1. Click a preset city button, or type a latitude, longitude, and UTC offset by hand, then click Update.
  2. Optionally click Use My Location to fill in coordinates from your browser — this only happens when you click it, and you can decline the permission prompt.
  3. Read sunrise, sunset, and day length, and watch the small sun dot move along the arc to show where the day currently stands.
  4. Check the moon phase name and shaded disc below the arc, then click Show Full Screen for a wall-ready view.

This screen works out today's sunrise, sunset, day length, and current moon phase for any location, then draws the sun's path across the sky as a simple arc so a classroom can see at a glance whether it's morning, midday, or evening where the location sits. Pick one of five preset cities, type in a latitude and longitude by hand, or click Use My Location to ask the browser for your device's coordinates just once, on demand. The moon phase is shown as a shaded disc alongside its name, from New Moon through Full Moon and back. Everything is calculated with a standard sun-position formula and a lunar-cycle calculation, entirely inside your browser, so the display keeps working even with no internet connection, and nothing about your location is ever sent anywhere.

Frequently asked questions

How accurate are the sunrise and sunset times?
The tool uses the standard NOAA solar-position formula and is accurate to within a few minutes for most locations and dates. It does not account for local horizon obstructions (hills, buildings) or unusual atmospheric refraction, which can shift the visible sunrise or sunset by a few extra minutes.
Do I have to allow location access to use this?
No. Location access is entirely optional and only requested when you click Use My Location. You can always type a latitude and longitude manually or pick one of the preset cities instead, and if you decline the permission prompt the tool keeps working normally.
How is the moon phase calculated?
It counts the days elapsed since a known new moon and divides by the average length of a lunar cycle (about 29.53 days) to get a phase fraction, which is then mapped to one of eight named phases such as First Quarter or Waning Gibbous. This is the same method used in most simple moon-phase calendars.