# Sunrise Calculator
> Static HTML calculator for sunrise, sunset, golden hour, day length, and solar noon for many cities worldwide.

## What this site is
Sunrise Calculator is a set of static HTML pages that show sun times for a chosen city. The home page defaults to Johannesburg and includes an interactive globe; city pages and the golden-hour page use the same solar math in the browser.

## What data it provides
- Sunrise and sunset times (NOAA-style zenith 90.833°)
- Golden hour / civil dawn and civil dusk (sun 6° below the horizon)
- Day length (sunrise to sunset)
- Solar noon
- Coverage for many cities via dedicated pages

Times are not fixed in the HTML as permanent clock values for "today"; they are computed in the visitor's browser for the visitor's date from each page's city coordinates.

## Key pages
- Home: https://sunrise-calculator.netlify.app/index.html
- Golden hour: https://sunrise-calculator.netlify.app/golden-hour.html
- AI summary: https://sunrise-calculator.netlify.app/ai.html
- Example — Cape Town: https://sunrise-calculator.netlify.app/sunrise-cape-town.html
- Example — Johannesburg: https://sunrise-calculator.netlify.app/sunrise-johannesburg.html
- Example — London: https://sunrise-calculator.netlify.app/sunrise-london.html
- Example — New York: https://sunrise-calculator.netlify.app/sunrise-new-york.html
- Example — Tokyo: https://sunrise-calculator.netlify.app/sunrise-tokyo.html
- Example — Sydney: https://sunrise-calculator.netlify.app/sunrise-sydney.html
- Sitemap: https://sunrise-calculator.netlify.app/sitemap.xml

## City page naming
City pages are named `sunrise-{slug}.html` (lowercase, hyphenated slug).

## Blog
- https://sunrise-calculator.netlify.app/blog/equinox-explained.html
- https://sunrise-calculator.netlify.app/blog/longest-day-of-the-year.html
- https://sunrise-calculator.netlify.app/blog/daylight-saving-time.html