Eos — Golden Hour Planner

Eos tells you when the light will be good where you are — and, unlike most sky apps, whether you'll actually be able to see it.

Every calculation that can run on your phone does. The sun and moon maths, the eclipse geometry, your saved spots, your reminders — all of it works with the radio off. No account, no sign-up.

WHAT'S WORTH SHOOTING, AND WHEN

• Golden hour, blue hour, sunrise, sunset and solar noon for today and any day ahead
• Moon phase, illumination, moonrise and moonset
• An agenda of the next 7, 14 or 30 days, with each window scored against the cloud forecast so you can see at a glance which evening is worth the drive
• Milky Way nights, meteor showers, supermoons, conjunctions, aurora, Space Station passes and noctilucent clouds

THE LIGHT ITSELF

• A colour forecast that reads the high, mid and low cloud separately — because a thin deck up high is what makes a sunset burn, and a solid deck down low is what kills it
• Real sunrise and sunset times behind hills and mountains, not a flat horizon

ECLIPSES, PROPERLY

• How much of the sun is covered from exactly where you stand, not the headline figure for the country
• The view at maximum, drawn from the real geometry
• Whether the sun will still be above your skyline when it happens — the question that decides a low-sun eclipse
• A clearance map of the ground around you, and your saved spots ranked by which has the cleanest view

TOOLS FOR THE SHOT

• Plan a shot — when the sun or moon lines up behind a landmark
• Plan the frame — how big the disc will sit at your focal length and sensor
• Sky AR — point your phone and see where the sun, moon and Milky Way will be
• A shoot journal that keeps your photo next to the conditions Eos predicted

ALSO

• Reminders and a wake-up alarm for the windows you care about
• A home-screen widget
• A shareable plan card
• English, French, Spanish, Italian and German

A few features reach for the internet — cloud cover, terrain heights, aurora, Space Station orbits, map tiles. Every one of them is additive. Lose signal and you still have the full sun, moon and eclipse picture.

Terrain uses a ground-height model, so it knows about mountains but not trees or buildings. Times can be a few minutes out.