Sunset Alarm – Online Snooze Based on Tonight's Sunset Time

A sunset alarm is a smart alarm that triggers based on the time the sun sets at your location. Instead of setting a fixed time like 7:00 PM, you set an offset relative to sunset — for example, 30 minutes before sunset. This way, your alarm automatically adjusts as sunset times change throughout the year. It's perfect for photographers capturing golden hour, evening runners, or anyone who wants to align their schedule with natural daylight.

We use the sunrise-sunset.org API, which calculates sunset times based on your precise latitude and longitude coordinates. The accuracy is typically within 1-2 minutes of the actual astronomical sunset. Factors like elevation, atmospheric refraction, and local terrain can cause slight variations, but for all practical purposes — photography, fitness, daily planning — the accuracy is excellent.

Sunset times change daily due to Earth's axial tilt (23.5°) and its elliptical orbit around the Sun. This causes the length of daylight to vary throughout the year. Near the solstices (June and December), sunset times change slowly. Near the equinoxes (March and September), they can shift by 2-3 minutes per day. Our tool automatically fetches the latest sunset data so your alarm is always in sync.

When your sunset alarm triggers, you can snooze it for 5, 9, 15, or 30 minutes (customizable in settings). The countdown resets, and the alarm will ring again after the snooze duration. You can snooze multiple times. The classic 9-minute snooze is the default, inspired by traditional mechanical alarm clocks. To stop the alarm completely, use the Dismiss button.

Yes. This is a browser-based tool, and the alarm runs entirely in your browser tab. If you close the tab or navigate away, the alarm won't trigger. We recommend keeping this page open in a background tab. For the best experience, enable browser notifications so you'll be alerted even if the tab isn't active. On mobile, keep the page open and your device unlocked.

When you first use the alarm, your browser will ask for permission to show notifications. Click "Allow" to enable them. If you previously denied permission, you can reset it in your browser settings. In Chrome: go to Settings → Privacy & Security → Site Settings → Notifications, find this site, and change the permission to "Allow." Notifications ensure you don't miss the alarm even when the tab is in the background.

Golden Hour is the period shortly after sunrise or before sunset when daylight is warmer and softer — ideal for photography, with golden-red hues. Blue Hour occurs just before sunrise or after sunset when the sky takes on deep blue tones. Our tool shows these times based on your sunset data. Golden Hour typically spans ~30-40 minutes before sunset, while Blue Hour begins about 10-15 minutes after sunset and lasts ~20-30 minutes.

In regions above the Arctic Circle or below the Antarctic Circle, there are periods of midnight sun (24-hour daylight) and polar night (24-hour darkness). If the sun doesn't set on a given day, our tool will detect this and display a special message. The alarm feature will be temporarily unavailable for that date, but you can still check future sunset dates when the sun will set again.

No. Your location is only used in your browser to fetch the sunset time from the API. We don't store, track, or share your coordinates. The latitude and longitude are sent to the sunrise-sunset.org public API solely to calculate astronomical data. If you prefer not to share your GPS location, you can manually enter coordinates or select a nearby city from the quick-pick list.

A sunset alarm adapts to nature's schedule. If you're a photographer, you know golden hour shifts daily — a fixed 6:30 PM alarm won't work year-round. If you run, cycle, or walk in the evening, a sunset alarm helps you start before dark. It's also great for: reminding you to watch the sunset, triggering smart home routines, managing light-sensitive tasks, or simply staying connected to natural rhythms without manually checking sunset times every day.