Guwahati, Assam, India keeps Asia/Kolkata time. Every Vedic daily timing here, the Panchang, Rahu Kaal, Choghadiya and Muhurat, is built from Guwahati's own sunrise and sunset, not a single all-India (IST) table, so it is specific to Guwahati and shifts a little each day. Even within India, Guwahati's sunrise is not identical to Delhi's, so the daily windows shift accordingly. The live panel on each page is recalculated daily for Guwahati.
The live panel shows today's tithi, nakshatra, yoga, karana and vaara for Guwahati, updated daily.
The Panchang depends on local sunrise, and Guwahati's sunrise differs, so its tithi/nakshatra timings are specific to Guwahati.
Astronomically precise Rahu Kaal timings for 25 major Indian cities.