What is Day/Night Cycle Visualizer?

The Day/Night Cycle Visualizer calculates and displays sunrise, sunset, solar noon, and twilight times for any location and date. A visual arc shows exactly how the sun moves through the sky so you can plan photography, travel, or outdoor activities.

Calculations use the SunCalc algorithm, the same astronomical model that powers most weather apps and astronomy software. Enter a latitude and longitude, pick a date, and the tool returns sunrise, sunset, solar noon, golden hour windows, plus civil, nautical, and astronomical twilight times. A circular arc shows the sun's path through the day and a download button saves the data as a plain-text file you can drop into a photography plan.

How to use

1. Search for a city or place by name, type in latitude and longitude directly, or tap the Detect-location button. The tool auto-detects your current position if you allow geolocation.
2. Pick a date to see the full day/night cycle, including civil, nautical, and astronomical twilight periods shown as color bands.
3. Read the circular sun arc to see the sun's path through the day, hover or tap any arc segment for exact times, then use the download button to save the full summary as a plain-text file.

When to use

• Booking a golden-hour photoshoot or wedding ceremony at the exact minute the light flatters skin tones.
• Planning a hike or summit climb where you want to be off the mountain before astronomical dusk.
• Working a Ramadan suhoor and iftar schedule based on civil twilight in your city.

Result

A photographer planning a golden-hour shoot in Reykjavik in June sees sunrise at 3:02 AM and sunset at 11:58 PM (nearly 21 hours of daylight) and picks the best 30-minute window.

FAQ

What's the difference between civil, nautical, and astronomical twilight?

Civil twilight is when the sun is 0 to 6 degrees below the horizon; you can still read outside. Nautical is 6 to 12 degrees; the horizon is visible at sea. Astronomical is 12 to 18 degrees; only after this point is the sky fully dark for deep-sky imaging.

Are the golden hour times in the morning and evening always the same length?

No. Their length depends on your latitude and time of year. Near the equator golden hour lasts roughly 20 to 40 minutes; in summer at 60 degrees latitude it can stretch over an hour because the sun rises and sets at a shallow angle.

Why is the daylight duration close to 24 hours on certain summer dates?

Above the Arctic Circle (66.5 degrees) during summer the sun never sets, producing the midnight sun. The tool will report 24:00 daylight and skip the sunset row. The same goes below the Antarctic Circle during their summer.

How accurate are the times for serious astronomy?

SunCalc is accurate to about one minute for sunrise and sunset and a few minutes for twilight events. That's plenty for photography or planning, but for telescope tracking or eclipses use a dedicated ephemeris that accounts for atmospheric refraction in detail.

Does the tool know about daylight-saving time?

Yes. Times are returned in your local timezone, which already factors in DST. If you need UTC for filing a flight plan or coordinating across borders, take the displayed value and adjust for your timezone offset manually.

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