Sky on Your Birthday

The engine uses JPL Keplerian planet elements, valid from 1800 to 2050, and Schlyter’s lunar formulae. Checked against published records, it lands the Hunter’s Moon full instant within minutes and the 2020 Jupiter-Saturn conjunction within a tenth of a degree. Treat the Moon phase as reliable to the day and planet positions as good to about a degree.

Phase names here follow the same convention as Sky Tonight: each named phase covers the days around its quarter event, so a moon a day or two from First Quarter already carries that name. The illumination percentage is the precise number to compare with other sources.

Your zodiac sign is the traditional tropical sign, fixed to the seasons: twelve equal 30 degree signs starting at the March equinox. Your Sun constellation is the astronomical answer: the actual star pattern the Sun stood in that day, from the same constellation bands Sky Tonight uses. Precession has pulled them apart over about two thousand years, so the two often differ. Neither claims anything about personality or life. The values here are for the evening of your birth date; within a day of a boundary the section says so.

Your birth star is your nakshatra in the traditional system: the lunar mansion the Moon stood in, one of 27 divisions of the Moon’s path. This page shows the nakshatra for the evening of your birth date, sampled at 9 PM, while the traditional value uses the exact birth time. If the Moon sits near a boundary between two nakshatras, the section says so, and a panchangam with the exact birth time is the final word. This is a traditional reading, not a scientific finding.

No. Verdicts are for mid-northern latitudes in your time zone, which your browser reads locally. The date and name you enter are used only to compute this one result and to build the share link. Nothing is stored or sent anywhere.

Yes. The link carries your date and your name, so a shared link opens the same sky, and the share text reads in first person: the sky on MY birthday.