What the tool does
The classical Jain biographies record, for each of the 24 Tirthankaras, the birth star the Moon occupied at his birth. This tool finds the birth star the Moon occupied at yours, and tells you which Tirthankara, if any, is recorded under the same star. It uses the table on our page The Birth Stars of the 24 Tirthankaras, so the two always agree. If you already know your birth star, you can choose it directly and skip the birth details.
How your birth star is found
Your local birth time is turned into a universal time using the time zone in force at your birthplace on that date. The tool then works out where the Moon stood in the sidereal sky, which is the count used in Indian calendars, and divides the circle into 27 equal stars of 13 degrees 20 minutes each. The Moon crosses one star in about a day, so the date alone is not always enough. If you leave the time blank, the tool checks the whole day and shows every star the Moon passed through, with the Tirthankara of each.
If the Moon was close to the edge of a star at your birth, a few minutes of difference in the birth time could move you to the next one. The tool says so when that happens.
What the table records
Of the 24 Tirthankaras, 21 are recorded under the same star in the Shvetambara and Digambara textual lines. For three, the two lines differ. Sambhavanatha is recorded under Mrigashirsha in one line and Jyeshtha in the other, Vasupujya under Shatabhisha and Vishakha, and Dharmanatha under Pushya and Revati. The tool shows both readings, with the tradition named on each, unless you choose one tradition. Neither reading is wrong. They are two ancient lines of transmission.
If no Tirthankara matches
Twenty-seven birth stars cannot be shared out among 24 lives, and some stars carry more than one Jina while several carry none. If your star has no Tirthankara recorded, that is not a lack of anything. The texts record only what they record, and the tool says so plainly.
What sharing a star means
Sharing a birth star with a Tirthankara is devotional kinship, not destiny. The tradition’s invitation is simple: take particular joy in that Jina’s kalyanaka days, and let his story be the one you return to. It is not a claim that the Tirthankara shaped your life, and Jain teaching places the weight on your own effort and conduct. Sharing Mahavira’s star makes you his admirer, not his heir. You can read each Jina’s life on his own page, and the kalyanaka calendar lists the days sacred to each.
Where your own tradition comes first
The birth star is a matter of record, but the weight given to it differs between sanghs and families. If your sangh or your family keeps its own record, follow that. The Jain astrology guide explains how the tradition understands a birth star, and our corrections page is where a discrepancy can be reported.
Frequently asked questions
↳ Do I need my birth time?
It helps. The Moon changes its birth star about once a day, so without a time the tool shows every star the Moon passed through on your birth date and the Tirthankara of each.
↳ What if I already know my birth star?
Choose it from the list under the form. The birth details are then ignored and the tool shows the Tirthankara recorded under that star.
↳ Why are two Tirthankaras sometimes shown for one star?
Some stars carry more than one Jina in the records. Revati, for example, holds Anantanatha and Aranatha, and also Dharmanatha in the Digambara reading.
↳ Does sharing a star give me a special link or protection?
No. It is devotional kinship, a reason to take joy in that Tirthankara's story and kalyanaka days. Jain teaching rests on your own conduct and effort and not on a star.
↳ Where do the birth stars of the Tirthankaras come from?
They come from the Shvetambara biographies and the Digambara Tiloya Pannatti, cross-checked on our table page. They record what the tradition transmits, not a measurement of the sky.