Sunrise & Sunset

Sunrise & Sunset

Compute sunrise, sunset, dawn, dusk, solar noon, twilight phases, day length, and moon phase for any latitude/longitude and date. All calculations use the Meeus astronomical algorithms — no external API, no rate limits, instant results.

Data Model

• Sun events — sunrise, sunset, solar noon, dawn (civil/nautical/astronomical), dusk (civil/nautical/astronomical), day length.
• Moon phase — current phase name and illumination percentage for the given date.
• Location — specified by latitude (-90 to 90) and longitude (-180 to 180) in decimal degrees.
• Timezone — results returned in the requested timezone (defaults to UTC).

Gotchas

• Polar regions: Locations above ~66° latitude may have no sunrise/sunset on certain dates (midnight sun or polar night). The tool reports these conditions explicitly.
• Timezone names: Use IANA timezone identifiers (e.g. "America/New_York", "Europe/London", "Asia/Tokyo"). Invalid timezone names fall back to UTC.
• Date format: Accepts YYYY-MM-DD. Defaults to today (UTC) if omitted.