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Free Moon Sign Calculator

Find the Moon’s tropical zodiac sign for a birth date. If the birth time is unknown, check whether the sign stayed the same all local day or changed between two possibilities.

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Enter birth details

The UTC offset is the offset used at the birthplace on that date, including any daylight saving time. The Moon sign calculation is geocentric, so no coordinates are needed.

What is a Moon sign?

In an astrological chart, the Moon sign names the 30-degree zodiac section containing the Moon’s geocentric ecliptic longitude at a particular instant. The Moon moves through the zodiac quickly enough that a date alone can sometimes point to two signs. This tool compares the start and end of the local birth day and locates a sign change to the nearest minute when one occurs.

Why the UTC offset matters

A local calendar day starts at a different UTC instant in each time zone. Enter the civil offset actually in effect at the birth place; a current offset may differ from the historical one. If you know the recorded time, enter it for the calculated position at that instant.

Look up a birthplace and time zone → · Calculate the full birth chart → · Browse all twelve Moon sign meanings →

Method: apparent geocentric tropical longitude from Astronomy Engine 2.1.19 via this site’s independent chart engine. Precise time matters when the Moon changes signs during the local birth day. The sign labels are an astrological convention, not a scientific personality measurement.

Reading the result

When a birth time is known

Enter the recorded local date and clock time, plus the civil UTC offset in effect at the birthplace. The browser converts them to a UTC instant and calculates the Moon’s apparent geocentric tropical longitude. The result names the sign and degree at that instant. Coordinates are not required because this is a geocentric zodiac position, not a horizon angle.

When a birth time is missing

Leave the time-unknown option selected. The calculator samples the beginning and end of the local date. If the sign changes, it finds the first minute in the new sign and presents both possibilities, instead of assigning an arbitrary noon result. If the sign remains stable, it still withholds a precise birth degree. A daylight-saving transition during that date needs a separate historical offset check.

Read the result in context

A Moon sign is one part of an astrological chart, not a measured personality trait. The birthday, local date boundary, and historical time-zone rule matter before interpretation. For a wider view, the full birth chart combines the Moon with the Sun and other planets, and adds the rising sign only when a reliable time and birthplace are known.

Open the expanded Free Moon Sign Calculator view →