Zodiac Drift

Sidereal sign calculator

Birth details

Exact time Date only

Birth date

Local birth time

Timezone at birth

The browser’s local timezone is selected automatically. Replace it to calculate for someone born elsewhere.

Corrected Tropical

Corrected Sun sign

Select a birth date

Ready

Enter birth details to calculate

Corrected longitude—

Tropical longitude—

Traditional sign—

UTC moment—

Boundary information

Exact birth time is only necessary when the Sun changes corrected signs during that local calendar day.

Waiting for calculation—

Precession offset at the selected moment

Lahiri ayanamsa changes continuously over time

Offset: —

0° — reference alignment30° — one full sign

Local birth moment—

Timezone at birth—

How the calculation works

The familiar Western zodiac is tropical: 0° Aries is fixed to the March equinox. This calculator instead subtracts the Lahiri ayanamsa for the entered historical moment, then divides the resulting longitude into twelve equal 30° sidereal signs.

The timezone converts the recorded local clock time to a UTC instant using the browser’s historical daylight-saving data. Latitude and longitude are not needed for this geocentric Sun-sign calculation.

This is an equal-sign sidereal system. Literal IAU constellations are a separate unequal-boundary system and include Ophiuchus.