Our calculations and sources

Created and owned by Arpit Agarwala. This Panchang generates its own calendar data on the server and shows the location and conventions used.

Astronomical foundation

Daily Tithi, Nakshatra, Yoga and Karana use Swiss Ephemeris 2.10.03, Lahiri ayanamsa and bundled official Sun/Moon files, SHA-256 checked before use. User dates from 1900 to 2100 are supported. Transition search resolution is 0.25 seconds; that is a numerical resolution, not a guarantee of accuracy.

Upper-edge sunrise with standard refraction is the default. Geometric-center sunrise is selectable. Standard pressure, 15°C and zero observer elevation are assumed; real weather, terrain and a blocked horizon are not modeled. Polar dates with missing sunrise do not receive invented ritual windows.

Regional calendars, fasting and parana

Amanta and Purnimanta conventions, Adhika months, regional festival anchors and common fasting/parana rules are implemented. Full Vaishnava sampradaya precedence, every regional solar calendar and every temple festival are not covered. Provisional entries and sensitive boundaries are labeled. Ceremony-specific Muhurta needs additional assessment.

What has been checked?

The checked-in Drik comparison includes 185 checks across nine date/city samples in five cities, 2025–2027. Published reference times are minute-rounded; tests allow 120 seconds for element transitions and 90 seconds for solar events. This is a regression sample, not certification or endorsement by Drik Panchang.

Independent checking

Local generation is the default and has no Panchang API quota. Optional Prokerala checking compares a limited set of daily elements and solar events only when enabled by the operator; it does not independently verify festival or parana rules. The source card shows the active mode.

Swiss Ephemeris is subject to its AGPL or professional license. Calculation and hosting independence do not remove those license obligations.