lighthours

The best light of the day, as a calendar subscription

Productivity

Photography

Calendar

GitHub

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Hi Product Hunt, I'm a photographer, and the problem I kept having is a small one: the best light of the day lasts about an hour, it moves by a minute or two every day, and every tool that tells you when it happens is an app you have to remember to open. I never remembered. So lighthours is the version that doesn't need opening. You type a place — a city, an address, a postcode, never coordinates — and you get an iCal feed. Golden hour and blue hour then show up in whatever calendar you already use, next to the shoots you already have booked. It's a rolling subscription, so it tops itself up and never runs out. Two things I got stubborn about: Accuracy. Sun position is the full NOAA algorithm including atmospheric refraction, so it works with the apparent altitude — where the sun actually appears — rather than the geometric one. Near the horizon that's about two minutes, which is exactly where it matters. I checked it against an independent implementation across a full year at six locations from Reykjavík to Sydney: mean deviation 0.9 seconds over 12,709 comparisons. Near the poles, phases that don't exist are left out rather than given an invented time. Longevity. It's plain PHP and vanilla JS — no database, no build step, no dependencies. A folder you upload to the cheapest hosting you can find, MIT licensed. That's deliberate: I wanted a free tool that can outlive my interest in maintaining it. If I lose interest, anyone with five euros of webspace still has it. On the business model, since it's the fair question: there isn't one. No accounts, no ads, no tracking, no email required, no paid tier planned. The sun's position is a pure calculation, so there's no API to pay for and nothing to store — running it costs me a few euros a year. There's a coffee link in the footer and that is the entire extent of it. I'd love to hear where it gets things wrong. The failure mode I can't find on my own is a location where the times are simply off — so if you try your own and something looks wrong, that's the most useful thing you could tell me.