The Solar Time Calculator can easily convert clock time (standard or daylight saving time) to solar time and solar time to clock time.

Solar time is based on the position of the sun relative to a local position (longitude). Solar time usually differs from clock time, though the magnitude of the difference varies. Thus, solar noon (when the sun is directly overhead) generally occurs at a time other than exactly 12:00 PM clock time. This difference is up to about +/– 45 min for most locations and is caused by the two factors: date and location. The Solar Time Calculator uses these factors to calculate the actual solar time relative to the position of the sun.

Solar time is useful when conducting shading analyses, optimizing photovoltaic array orientation, and performing other calculations in the field of solar energy systems.

What’s New

Version 2.0

Enhanced user interface.

Ratings and Reviews

3.0 out of 5
1 Rating

1 Rating ,

Time zones are too few.

The App works. But. There are more than 24 time zone on the world. The App only has 5 time zone to be selected. And the interface is not optimized for iOS 12.

Dialist ,

Suggestion for improvement

To determine solar time to the nearest minute, you need to know the longitude to the nearest quarter of a degree. This app does not permit that fine a distinction - even when using gps to determine longitude. Using all available precision in determining longitude would greatly improve the app.

Alford67 ,

Needs an info section

Wanted to use an app to measure solar time in my area. Not sure this app does it because there are no basic instructions on how to use it. Would be nice to have something assist with finding my longitude also. You have to have all the info to use the app, so in the end you only spin dials. :-(


American Technical Publishers
45.6 MB

Requires iOS 7.0 or later. Compatible with iPhone, iPad, and iPod touch.



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    With Family Sharing set up, up to six family members can use this app.

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