Accurate Standard Time Sundials
A sundial is a fascinating device that uses the sun’s position to tell the time. It’s a simple and elegant way to measure time which has been used for thousands of years.
From a scientific perspective, sundials are invaluable tools for understanding the Earth’s rotation and the position of the sun in the sky. Studying them helps us understand the concept of solar time and how it differs from the timekeeping methods we commonly use.
This site offers a variety of sundial resources, including:
- Guides to understand sundial components and calibration techniques.
- Tool to create sundials (time of day and calendar sundials).
- Utility for tracking the sun’s position in the sky throughout the year.
- Simulation tool to understand sundial performance.
Types of Sundials
Although there are many types of sundials, this site focuses on horizontal sundials, both for tracking time of day and calendar dates.
Time of Day Sundial
| Sundial Base | Base where the hour lines are imprinted and the gnomon is fixed. |
| Gnomon | Part that casts the shadow onto the sundial base. |
| Hour Line | Line marking the shadow position at specific hours of the day. |
| Shadow Edge | Edge of the gnomon shadow that marks the current time. It moves along the hour lines as time progresses. |
| Sundial Center | Point in the sundial base where all the hour lines converge and the gnomon is fixed. |
| North-South Gnomon Slot | Slot in the sundial base where the gnomon fits. Also used to align the base with the polar north/south. |
| Gnomon Inclination | Angle between the sundial base and the gnomon, typically set to the latitude of the sundial’s location. |
Calendar Sundial
| Nodus | Pointed part that casts a shadow onto the sundial base. |
| Nodus Shadow | Shadow cast by the nodus. Its tip is used to determine the current month. |
| Declination Line | Line on the sundial base, representing the sun’s path on a specific day of the year. |
Sundial Tools
Time of day sundial builder
Create top accuracy printable sundial tunned for your location.
Calendar sundial builder
Create a printable calendar sundial illustrating the progression of seasons throughout the year.
Solar tools
Gather information about sunrise/sunset times, day length and other solar metrics for your location.
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