Help

Twilyte shows tonight’s sky and the day’s twilight for wherever you are: when the light goes, how dark it gets, and what’s worth a look. It’s free, with no account and no ads. If something here doesn’t answer your question, get in touch.

Get in touch

Questions, problems and ideas all go through the feedback form on GitHub. It needs a free GitHub account. Every message is read, and a reply comes back on the same page.

Your place

Twilyte asks for your location so it can work out the sky where you are. All the astronomy is worked out on your device. If you’d rather not share your location, tap the place name over the painted sky and search for a town, or type in coordinates. Your saved place stays on your device.

When Sky View doesn’t line up

Sky View uses your phone’s compass, which is easily thrown off. If the stars on screen sit away from the real ones:

1. Calibrate the compass. Wave the phone in a slow figure-8 for a few seconds, rotating your wrist as you go.
2. Move away from metal. Cars, railings and speakers pull the compass off, and so does a case with a magnet in it.
3. Align on something you can see. Tap Find, pick the Moon or a bright star or planet, hold the phone so the real one sits in the ring, then tap Align.

If it’s still wrong, open Sky View, tap Sensors, then Copy, and paste what it copies into the feedback form. Those numbers show what the phone’s sensors are reporting.

Twilight times for another day or place

The Ephemeris tab gives sunrise, sunset and every stage of twilight for any date and place, with golden and blue hours, moonrise and moonset. You can export a month to your calendar or a spreadsheet. The times agree with professional astronomy software to within a minute.

How dark your sky is

The Console says how dark your sky is on the Bortle scale, from 1 (the darkest sky on Earth) to 9 (an inner city). It’s worked out from NASA’s satellite measurements of light at night. If you know your sky is darker or brighter than that, open Settings, turn off Auto-detect from location, and choose it yourself.

Without a signal

Once Twilyte has loaded, the sky, the twilight times and Sky View all work without a connection. The weather forecast and place search need one. Offline, Twilyte shows the last forecast it fetched, if it’s less than a day old, and says how old it is.

Privacy

Twilyte doesn’t track you. The privacy policy lists everything it does with data.