Vedic astrology guide
Ayanamsa Is Why Two Panchangs Disagree
Lahiri is the sidereal offset these notes use. Another ayanamsa, or a tropical zodiac, can move a sankranti by a day or a rashi by a sign.
By Avinash ChandanPublished Updated
Ayanamsa is the angle between the tropical zodiac, tied to the seasons, and the sidereal zodiac, tied to the stars. Lahiri, also called Chitrapaksha, is the offset used here and in the Indian national panchang tradition. It is a bit more than 24 degrees. That is why a Western app can put the Sun in “Aquarius” in early February while a Jyotishi still has Surya in Makara until mid-February.
Inside Jyotish, smaller fights remain. True node or mean node moves Rahu’s ingress by hours or a day. A tithi taken at sunrise in Kolkata is not the sunrise in California. None of these is “the pandit being vague.” They are named choices. A calendar that will not say which ayanamsa it used is not a panchang. It is a poster.
What this site is committing to
Rashis in these essays are Lahiri. Times are IST unless a local sunrise is the point. Rahu, unless a sentence says otherwise, is the mean node of classical Jyotish. If your family panchang is also Lahiri and still differs by a day, the next question is the sunrise rule, not a new philosophy.
The solstice gap is Makar Sankranti and December.
Questions people keep asking
Is Lahiri the only ayanamsa?
No. It is the one used for Indian government panchangs and for these notes. Others exist. Mixing them without saying so creates fake disagreements.
Can ayanamsa change a Moon sign?
Near a rashi boundary, yes. That is why a birth time and a named ayanamsa belong together.