How We Calculateगणना पद्धत

Astronomy

Positions of the Sun and Moon come from the open-source Astronomy Engine library, which is accurate to well under a minute of arc. Sidereal (nirayana) positions use the Lahiri (Chitrapaksha) ayanamsa, the standard adopted by the Government of India's Rashtriya Panchang. We do not use a printed panchang as input.

Reference place

Sunrise, sunset, moonrise and every day-based rule are calculated for Mumbai (19.08° N, 72.88° E) in Indian Standard Time. Sunrise is the moment the upper edge of the Sun appears, with standard refraction. In Nagpur the Sun rises about 25 minutes earlier, which very occasionally changes the tithi at sunrise.

Tithi, nakshatra, yoga and karana

A tithi is each 12° step of the Moon's elongation from the Sun. The tithi of a day is the one current at sunrise. Nakshatra and yoga are 13°20′ divisions of the Moon's sidereal longitude and of the sum of the Sun's and Moon's longitudes. Karana is half a tithi. End times are to the minute.

Months

Months are amanta. A month is named after the sign the Sun enters during it (Chaitra is the month in which the Sun enters Mesha). A month with no solar ingress is adhik and takes the name of the following month.

Festivals

Each festival has a rule: a month, a tithi and the part of the day in which the tithi must prevail, such as madhyahna for Ganesh Chaturthi, aparahna for Dasara, pradosh for Lakshmi Pujan, midnight for Mahashivratri and Gokulashtami, and moonrise for Sankashti. When the tithi prevails at that time on two days we take the first; when on neither, the day on which it is current at sunrise. The rule is printed on each festival page.

For 2026 we compared every calculated festival that is also a state holiday with the Government of Maharashtra notification: Mahashivratri, Holi (Dhulivandan), Gudi Padwa, Ram Navami, Mahavir Jayanti, Buddha Pournima, Ganesh Chaturthi, Dasara, Lakshmi Pujan, Balipratipada, Bhaubeej and Guru Nanak Jayanti. All of them matched.

Ekadashi and Sankashti

Ekadashi follows the Smarta rule: the day on which Ekadashi is current at sunrise. Sankashti is the day on which Vadya Chaturthi is current at moonrise in Mumbai.

Muhurat

Muhurat pages screen every day against the published rules for that ceremony, including combustion of Jupiter and Venus. They are candidate dates, not a personal muhurat.

Where printed calendars may differ

• A calendar made for another city can move a festival by a day when a tithi changes close to sunrise or moonrise.
• Some panchangs use other ayanamsas or older (grahalaghava) methods.
• Communities follow their own rules for some festivals, such as Pola or Gokulashtami.

Corrections

If you find a date that differs from your panchang, write to [email protected] with the date and the name of your panchang. We check every report.