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HowLongDay
Sunrise, sunset & daylight calendar for 49,000+ cities
HowLongDay shows exactly how much daylight you'll get today — sunrise, sunset, golden hour, blue hour and day length — for any of 49,000+ cities worldwide, down to the minute. No sign-up, no ads blocking the data, just the numbers you need for planning a shoot, a round of golf, a hike, or a flight before dark. Every city also gets a full year-ahead daylight chart and month-by-month calendars, so you can see how the light will change before you book the trip.
Hey Product Hunt 👋
I built HowLongDay because I kept doing the same mental math before trips and activities: "what time does it actually get dark there in October? Google's instant answer gives you today's sunset, but not the shape of the whole year.
Every city page is generated from real astronomical calculations (SunCalc), not an API lookup — so it works for genuinely obscure places, not just capitals. Would love feedback on which cities/features to prioritize next (thinking: activity-aware planning — "how long can I golf before dark" style).
Love how clean the data is and the year-ahead chart is a nice touch for trip planning. One thing that would help me a lot is adding a "compare two cities" view, so I can see side by side how the daylight shifts between where I live and where I'm traveling to. Would make picking dates way easier.
Pulled up my city and the golden hour timing matched my watch perfectly, which is more than I can say for most weather apps. The full year chart is a nice touch for planning trips around the light.
Finally tried this out for a sunrise shoot next month and the golden hour window being down to the minute is honestly super handy. Basically everything I needed without having to dig around three different sites.
About HowLongDay on Product Hunt
“Sunrise, sunset & daylight calendar for 49,000+ cities”
HowLongDay was submitted on Product Hunt and earned 5 upvotes and 4 comments, placing #149 on the daily leaderboard. HowLongDay shows exactly how much daylight you'll get today — sunrise, sunset, golden hour, blue hour and day length — for any of 49,000+ cities worldwide, down to the minute. No sign-up, no ads blocking the data, just the numbers you need for planning a shoot, a round of golf, a hike, or a flight before dark. Every city also gets a full year-ahead daylight chart and month-by-month calendars, so you can see how the light will change before you book the trip.
HowLongDay was featured in Travel (42.4k followers), Calendar (32k followers) and Nature & Outdoors (886 followers) on Product Hunt. Together, these topics include over 16.7k products, making this a competitive space to launch in.
Who hunted HowLongDay?
HowLongDay was hunted by Heikki Aura. A “hunter” on Product Hunt is the community member who submits a product to the platform — uploading the images, the link, and tagging the makers behind it. Hunters typically write the first comment explaining why a product is worth attention, and their followers are notified the moment they post. Around 79% of featured launches on Product Hunt are self-hunted by their makers, but a well-known hunter still acts as a signal of quality to the rest of the community. See the full all-time top hunters leaderboard to discover who is shaping the Product Hunt ecosystem.
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Heikki Aura