Hora Solis

A Roman clock dividing day and night into temporal hours

Hora Solis is a digital reinterpretation of ancient Roman timekeeping — a system that aligns the day not with factory clocks or timezones, but with the movement of the sun across the sky.

Unlike modern timekeeping, which divides every day into 24 identical hours regardless of season or place, the Roman system divides daylight into twelve equal hours (horae) and night into four watches (vigiliae). The length of these hours shifts with the seasons — shorter in winter, longer in summer — because the sun sets the pace.

This project presents Roman time in a visual, intuitive form. It doesn’t just tell you the hour — it shows how the shape of the day is changing around you.

Why this matters

Modern time exists to synchronize us. Timezones, standardized hours, and daylight saving are tools of industry — designed for factories, offices, and global schedules. They reduce time to something fixed and mechanical: a uniform rhythm imposed everywhere, detached from place, light, and season.

But natural time isn’t uniform. The sun doesn’t rise at 6:00 every day. Days lengthen and shorten, light shifts, and with it, our sense of being changes — even if the clock doesn’t reflect it.

Roman timekeeping invites us to see time differently: not as a grid to obey, but as a rhythm woven into the fabric of life. It expands and contracts with the sun, flows with the day, and settles into the night. It restores a deeper awareness of time — not as something measured, but as something lived.

You may find yourself planning your day differently — setting aside the evening vigiliae for quiet work, time with family, reading, or creative focus. If you follow a biphasic sleep rhythm, you might align your shorter rest with midday or early night, letting the first hours of darkness become a calm, intentional space. Or perhaps you’ll discover the quiet clarity of early morning, just as the world begins to wake.

May this project help you rediscover your own rhythm.

What the interface displays

The following reflects the Roman system of daily time:

Supporting Hora Solis and future projects

If you appreciate the work behind Hora Solis, consider supporting its founding author. Your support honors the time and dedication already invested and helps make room for reflection, new ideas, and future projects beyond this one.

Donate with Bitcoin – bc1qn3cy5hg9esu8tt3kpq2t0khhjmqz7tmxpxfn4s

Donate with Bitcoin, QR code

If you find this project helpful, share it with others who might like it — whether it’s chatting with friends or posting about it on social media. Every little mention helps it reach someone who might really appreciate it.

Future roadmap

These are some directions the project may take moving forward:

  1. Sleep configuration and multi-phase sleep
    Customizable sleep schedules, including support for segmented and other polyphasic sleep patterns.
  2. Adjustable solar event angles
    More precise control over when sunrise and sunset are considered to occur, by setting how far the sun is below the horizon.
  3. Task planning
    Ways to organize the day around natural light and solar rhythms.
  4. Calendar integration
    Syncing with external calendar services to keep everything aligned.

Bringing these ideas to life will take time and effort. Whether or not they happen depends on how much interest the project receives. Donations are one way to show support and help shape what comes next.

License and Contributing

For licensing details and contribution guidelines, visit the project on GitHub.