Gyan Sagar is a digital resource for Hindu calendars, Vedic astrology and astronomy, bringing traditional knowledge and location-specific calculations together in one place. Its free tools use a visitor’s city and local sunrise to present daily Panchang details, including tithi, nakshatra, yoga, karana, sunrise and sunset, Rahu Kaal, Choghadiya and planetary hora. Users can explore Hindu calendar dates, monthly muhurat calendars, auspicious timings and guidance on traditional principles for choosing a suitable time.

The site also provides tools for creating birth charts, including Lagna Kundali and Navamsa, and for Kundali matching using the Ashtakoota system. Astrology features cover dashas, planetary transits, dosha calculations, Ashtakavarga, horoscopes, numerology, nakshatra-based name letters, gemstones, Rudraksha and Porutham matching. Visitors can find vrat and festival dates, ritual information and articles on Vedic knowledge. Astronomy resources include eclipse calendars and planetary positions. Gyan Sagar describes its calculations as combining an in-house astronomical engine, classical rules and testing, and offers a Panchang API for developers.