Solar Time Calculator



Calculating solar time is essential for various applications, such as astronomy, navigation, and solar energy systems. A Solar Time Calculator provides a convenient way to determine solar time based on the observer’s location and date. In this article, we will explore how to use a Solar Time Calculator, the underlying formula, an example scenario, and frequently asked questions.

How to Use

To use the Solar Time Calculator, input the required parameters and click the “Calculate” button. The calculator will then provide the accurate solar time based on the specified location and date.


The formula for calculating solar time involves adjustments for the observer’s longitude, the equation of time, and the time zone offset. The precise formula is:


  • is the observer’s local time.
  • is the observer’s longitude in degrees.
  • is the standard meridian for the observer’s time zone.
  • is the correction factor accounting for the Earth’s elliptical orbit.


Suppose an observer is in New York City (Longitude: -74.0060°) on June 21, 2023. The standard meridian for Eastern Standard Time is -75°. Let’s calculate the solar time:

For simplicity, let’s assume . If the local time is 12:00 PM, the solar time can be calculated accordingly.


Q: Why is solar time different from standard time?

A: Solar time accounts for the Earth’s axial tilt and elliptical orbit, leading to variations in the length of a solar day.

Q: How accurate is the Solar Time Calculator?

A: The calculator provides precise results when considering factors like longitude, equation of time, and time zone adjustments.

Q: Can the calculator be used for any location worldwide?

A: Yes, by inputting the observer’s longitude and the standard meridian for the respective time zone.


The Solar Time Calculator is a valuable tool for accurately determining solar time, considering the Earth’s complex movements. Whether you’re an astronomer, navigator, or involved in solar energy, this calculator ensures precise results for your applications.

Leave a Comment