Hindu Calendar 2031

Two sites can print different dates for the same festival and both be honest about it, because a pañcāṅga depends on choices that are rarely stated. Ours are stated here and do not change silently.

• dṛk gaṇita (observation-based), not vākya — positions are taken from the Swiss Ephemeris rather than from the medieval tables, which is what the mainstream Indian published pañcāṅgas do.
• Lahiri (Citrāpakṣa) ayanāṁśa, the Indian civil standard. It does not affect tithi, nakṣatra, yoga or karaṇa at all — those depend only on the angle between the sun and the moon — but it does place the sidereal rāśi, and so it is stated.
• Sunrise decides the day. The tithi of a date is the one running at that place's sunrise, not at midnight, and not the one that occupies most of the day.
• Months are pūrṇimānta — each runs full moon to full moon, the northern reckoning. It only affects the kṛṣṇa pakṣa, and it is the difference between calling one night “Phālguna Kṛṣṇa Caturdaśī” and “Māgha Kṛṣṇa Caturdaśī”: Mahāśivarātri either way, named differently north and south.
• Rise and set follow the standard convention — upper limb, with refraction. Where no place has been chosen, New Delhi is used.
• ∆T is applied. The ephemeris integrates in Terrestrial Time while clocks run on Universal Time, and the two differ by about 69 seconds this decade. Applying it is why our times can sit a minute later than almanacs that do not.

Nothing here is scraped from another calendar site, and nothing is generated by a language model: a date is arithmetic on the positions of the sun and the moon, with one right answer, and it is computed. Dates are computed through December 2036; beyond that the site says so rather than guessing.