New feature: Solar Time Conversion

As many of you know, a local time recorded at a person’s birth is not exactly correct because of GMT zones and Daylight Savings, so often it turns out that Hour Pillar is wrong. Sometimes, but rarely, the entire chart can be wrong if the person is born during the transition between two years and the difference between local and solar time is significant.

There are some tools out there that can help you convert local time into accurate solar time, but we decided to have that tool built-in for practical reasons.

So from now on, when you open the date input page, you will see three additional fields. We will explain them in detail here so you can use them properly.


The planet Earth is divided into GMT zones ranging from -12 to +12. So, for example, if you are born in Berlin, your GMT zone would be +1, and that’s what you have to put in this field.


Most countries change clocks twice a year for Daylight Savings purposes. Each country has a different schedule, so you should check whether Daylight Savings was active at birth. On this website, you can check all major cities for their historical DST changes

So if your city of birth had active DST during your birth, you have to put this option to YES.


The exact position of a person’s birth is crucial to determine the exact Solar time. To do that, we can simply Google our place of birth to give us coordinates. For example, this is a Google search for Berlin’s longitude, which is +13.40

The longitude can range from -180 to +180. Please make sure that you don’t take the wrong value. Longitude goes from west to east, and that’s the value we need, while latitude goes from north to south, which is irrelevant in our case.

If you would like to find out birth information for a celebrity, you can use; it has a large database that includes the exact time of birth and location, which is very useful

The Solar Time feature is already live in our Chrome Extension and should appear on iOS and Android shortly, as version 5.1.

Also published on Medium.