🪔 Hindu Festival Calendar

Every festival is derived from the Swiss Ephemeris–backed Panchang: tithi (lunar day), nakshatra (lunar mansion), paksha (waxing/waning), and sidereal sankranti (Sun's sign change). No AI, no rough estimation — pure deterministic compute. Cusp festivals (those near sunrise tithi rollover) may differ by ±1 day from your local pandit depending on city; that is normal and matches how published almanacs handle the boundary.

Amanta: lunar month ends at the new moon (amavasya). South India and Maharashtra use this convention. Purnimanta: lunar month ends at the full moon (purnima). North India uses this. The same calendar day can sit in different lunar months under each convention — for example, the day called 'Kartika Krishna Amavasya' in the north is 'Ashwin Krishna Amavasya' in the south, but it's the same day of Diwali. AstroLumina names festivals using their conventional published name; the underlying date is identical across regions.

Most festivals are pan-India (Diwali, Holi, Maha Shivaratri) and fall on the same date everywhere. A handful are regional: Pongal is solar (Makar Sankranti = mid-Jan); Onam follows the Bhadrapada Shravana nakshatra (Kerala-specific); Karva Chauth is observed primarily in North India; Bihu follows the solar Mesha Sankranti and is Assamese. The region picker filters the calendar to what your community actually observes.

Yes. Tap 'Add to Google Calendar' to open Google's subscribe-by-URL flow, or 'Download .ics' to import once into Apple Calendar / Outlook. Both refresh automatically — when AstroLumina adds future-year dates or improves accuracy, your calendar app picks up the changes on its next sync (typically every few hours).

Ekadashi: the 11th tithi of each lunar fortnight, observed as a fasting day for Vishnu (24 a year, with month-specific names like 'Mokshada Ekadashi'). Pradosh Vrat: the 13th tithi, observed in the pre-dusk window for Shiva. Sankashti Chaturthi: the 4th tithi of the Krishna paksha, dedicated to Ganesha for obstacle removal. Vinayaka Chaturthi: the 4th tithi of the Shukla paksha, also Ganesha. All four recur every lunar month and appear automatically in every region's view.

Yes — Swiss Ephemeris is accurate from 5400 BCE through 5400 CE for Sun and Moon positions. The current page defaults to the present month; navigate forward or back to view any year. Lat/lon affects only same-day cusp festivals (where the tithi rolls just before or after sunrise at your location); for those, AstroLumina defaults to the India centroid which matches the dates major almanacs publish.