Moon sign calculator
Find the Moon’s tropical zodiac sign at your birth instant. Enter the local clock time and select its time zone; the result uses the Moon’s geocentric longitude, not its visible phase.
Before you start
Use the time recorded at the birthplace, not your current time zone. The city presets use approximate city centres. Select exact coordinates for a more precise location; north and east are positive, south and west negative. A Moon-only result needs the time zone but not the geographic coordinates.
How the calculation works
The browser converts the local time using its IANA time-zone database, including historical daylight saving rules where available. Astronomy Engine 2.1.19 supplies geocentric tropical longitudes of date. Each 30° interval is a sign. The ascendant is the eastern intersection of the ecliptic and the geometric horizon, without atmospheric refraction.
A repeated clock time during an autumn change can represent two instants: the tool asks you to choose. A clock time skipped during a spring change is rejected. Ascendant calculations are limited to latitudes from 65° south to 65° north. Dates before 1900 and future instants are not supported. Browser time-zone history and approximate input can affect results near a boundary.
Frequently asked questions
What if I do not know my birth time?
Do not enter an invented birth time. You can use the date-only Sun sign tool, which reports uncertainty. The Moon and especially the ascendant may change during the day; this tool cannot establish them confidently without a time.
Why can two websites disagree?
Check the local time, daylight saving choice, coordinates, tropical versus sidereal zodiac, and geocentric versus topocentric Moon. Small rounding differences are possible. This tool shows the UTC instant and degrees to make comparison easier.