Every ayanamsa, one chart Another site says your rasi is different. Here is why, and here is the whole of it: your own chart read under all 9 conventions this app offers, side by side, with every placement that really changes marked. Most of them do not change at all.

Enter the date of birth.

A tropical longitude is measured from the vernal equinox, which drifts westward about fifty arc-seconds a year. Indian astrology measures from a fixed point among the stars instead, so every position here is the tropical one less an ayanamsa: the angle between the two zero points. Subtract a different ayanamsa and every graha slides by the difference.

Where exactly that fixed point sits is a convention and not a measurement. No observation settles it. The Indian Calendar Reform Committee fixed one value in 1955 and the Rashtriya Panchang has printed it since; B. V. Raman's readers use his; Krishnamurti Paddhati uses Krishnamurti's; Western sidereal astrology uses Fagan–Bradley; and two of them are recomputed at every instant so that a named star sits exactly at its nominal degree.

This app's default is Lahiri. That is a choice about readers, not about astronomy: it is what most Tamil and North Indian almanacs print, so it is the reading a family is most likely to be holding in their hand. It does not make any of the others wrong, and a reader whose family astrologer works in Raman or in KP should put the app on that — the picker is at the foot of this page, and every chart on every other page follows it. Computed, classical, believed sets out which parts of this almanac are astronomy and which are convention; the method page gives every definition and its constants.

Enter a date, a time and a place above, and this page casts the same chart once under each of the 9 conventions, and prints the 10 placements side by side — the nine grahas and the lagna — with the rasi, the nakshatra and the pada each one gives.

The usual result is that most of those placements are identical under every one of the conventions, and the one or two that are not were already sitting within a few degrees of a boundary. The page says which boundary, how far from it, and how many minutes of clock that gap is worth at that graha's own speed — because for almost every chart the remembered birth time is a larger doubt than the choice of convention, and that is worth knowing before an argument starts.

Only the lagna needs the time of birth to be right: the other nine placements move by minutes of arc over an hour, so a time remembered to the nearest half hour changes none of them. If the time is not known at all, tick the box in the form and read the table without the lagna row.