☀️ Solar Calendar
The Solar Calendar is a fresh, easy-to-follow calendar system that stays naturally in sync with the Earth’s orbit around the sun.
Instead of uneven months, it gives us 13 months of 28 days — each with exactly 4 full weeks. The year always begins with the Spring Equinox (when day and night are equal), and it uses two special days to stay perfectly aligned:
- Equinox Day — the real astronomical start of the year
- Solstice Day — a leap correction day added after August during leap years
🌍 Best of all:
- It removes the need for daylight savings time
- It fixes the old calendar naming problem — now September, October, November, and December are once again the 7th, 8th, 9th, and 10th months — as their names suggest
This project shows:
- A full Solar Calendar (starting with 2025) with each day matched to the standard Gregorian date
- A full Gregorian Calendar with each day mapped to its Solar Calendar equivalent
It’s an experiment in re-thinking how we measure time — to make it simpler, fairer, and more human.
🌍 View the Calendars Online
You can view the calendars here:
🔄 GitHub Repository & Pages Site
🔭 What is the Solar Calendar?
- 📅 13 months, each with exactly 28 days — no short or long months
- 🗓️ Every month starts on a Monday — easy to plan, easy to remember
- 🌱 The year begins on the first Monday on or after the Spring Equinox
- ☀️ Equinox Day marks the real astronomical start of the year — outside of months and weeks
- 🔁 Solstice Day is added after August in leap years to keep the calendar perfectly synced
- 🕰️ No more daylight savings time — the calendar flows with the sun naturally
- 🧠 Names finally make sense again:
- September is month 7
- October is month 8
- November is month 9
- December is month 10
- ✅ No drifting, no guesswork — it’s aligned with the Earth’s actual orbit
🧠 Features
- Full Gregorian calendar display
- Overlay with corresponding Solar Calendar dates
- Accurate solar year rollover
- Leap-year Solstice Day support
- Equinox Day marking
- Clean, responsive HTML/CSS grid layout
- Efficient, recursion-free JavaScript logic
🙌 Contributing
We welcome contributions! Please read our contributing guidelines to get started.
📄 License
This project is licensed under the GNU General Public License v3.0.
🚀 Getting Started
- Clone the repo:
git clone https://github.com/tomgould/solar-calendar.git
cd solar-calendar
- Open
solar-calendar.html or gregorian-calendar.html in your browser — no build tools required!
🙋 Questions?
Open an issue and we’ll get back to you!
Thanks again!
– Tom ☀️