Why a fixed alarm misses the light
You know when the light is good. The problem is that it moves: sunset in New York runs from 16:31 on 21 December to 20:30 on 21 June. A fixed alarm for golden hour is wrong within two weeks and useless within a month.
Risetime sets an alarm on the sun's angle rather than on a clock time — and the angle is what actually defines those windows.
The light, by angle
| What you're after | The sun is… | In Risetime |
|---|---|---|
| Golden hour, evening | below about 6° above the horizon | a solar angle anchor, +6° evening |
| Blue hour, evening | between about 4° and 6° below | −4° evening, the window running on to −6° |
| Golden hour, morning | the same, in reverse | +6° morning |
| Astronomical night | 18° below | −18° evening, and −18° morning for when it ends |
Definitions vary between photographers; these are the common ones. Set the angle you work with and the app holds it at every latitude and season — which a "30 minutes before sunset" rule of thumb cannot do, because the length of twilight changes with both. In London on 21 June, +6° falls at 20:27 and sunset at 21:21: nearly an hour apart. In New York the same evening, 19:49 and 20:30: forty minutes.
Make the anchor once
- Open Settings → Anchors and press +.
- Keep the type on A solar angle, and set your angle — tap the value to type it, and choose morning or evening.
- Name it — Golden hour, Blue hour, Night sky — pick a colour, and save.
- On the Alarms tab, set an alarm on it: at the anchor, or thirty minutes before to reach the spot.
A working week, and the light at the weekend
Most of us are not shooting for a living:
| Moment | Alarm | Days |
|---|---|---|
| Wake-up | 06:45 | Mon–Fri |
| School run | 08:10 | Mon–Fri |
| Pack the bag | 30 min before Golden hour | Sat & Sun |
| Blue hour | Blue hour | Sat & Sun |
| Stars | Night sky | Fri & Sat |
Clock alarms for the week, sun alarms for the light — the same list, the same app.
On the road, and off the grid
- Travelling? Turn on Auto-update location in Settings and your alarms follow you — a trip, a new city, a coastline.
- No signal at the spot? Risetime computes the sun's position on the phone, with an astronomical library. It has no internet permission at all, so it cannot depend on a connection: airplane mode, a canyon, a boat — the alarm still knows when the light comes.
- No tracking, no account, no ads. Your location never leaves the phone. Privacy policy
For the night sky
Astronomical night is the window between the evening and the morning moments when the sun is 18° below the horizon. Set an anchor at each and you hold both ends of the dark.
Far north or far south, that window closes for part of the year: in London the sun does not reach −18° from 23 May to 21 July. Risetime says so when you create the anchor, with the dates for your own location, and on those nights the alarm stays silent rather than ring at a time the sky never produces.
What Risetime does not do: the Moon. No moonrise, no phase, no lunar calendar — the app will not tell you when a full Moon washes out the Milky Way. It does the sun, and it does it offline.
What it costs
Risetime is free for up to three alarms and three timers — for good. Need more? Use those three first, and see if it's worth your support: supporters get unlimited alarms and timers, yearly or once. If not, I'll be happy to hear you out.
Never miss the light again.
Google PlayOpen testingRisetime is in open testing, so you join the test first and install from Play afterwards. Without that step Play may tell you the app isn't available in your country.