Today's Rahu Kaal in Varanasi with exact start and end times in local time. Rahu Kaal is the daily inauspicious window — best avoided for starting important work or journeys.
Rahu Kaal is the eighth part of the daytime — sunrise to sunset divided by eight — and which of those eight parts it falls on depends only on the weekday. Because the division starts at Varanasi's own sunrise, both the start time and the length of the window shift here through the year rather than sitting at a fixed clock time.
All of India keeps one clock — IST, pinned to the 82.5°E meridian — across roughly 28° of longitude. Varanasi lies at 82.97°E, so the Sun reaches its highest point here about 2 minutes earlier than the clock suggests. That puts solar noon in Varanasi roughly 23 minutes earlier than in New Delhi; sunrise moves with it, though latitude shifts sunrise a little further either way as the seasons turn. Rahu Kaal, Choghadiya and every muhurat are carved out of local sunrise and sunset, so a table copied from a Delhi panchang is wrong for Varanasi by about that much.
Varanasi sits at 25.32°N. Daylight here runs to about 13h 35m at its longest and about 10h 25m at its shortest — a swing of roughly 3h 09m across the year. Because the eight daytime Choghadiya periods are made by dividing sunrise-to-sunset into eight equal parts, each period in Varanasi is noticeably longer in summer than in winter. Rahu Kaal, being one-eighth of the day, moves the same way.
Timings are computed for 25.32°N, 82.97°E (Asia/Kolkata) with the Swiss Ephemeris: the day's exact sunrise and sunset first, then Rahu Kaal, the Choghadiya periods and the panchang limbs derived from them. Nothing is approximated from a nearby larger city.
Not if you want it exact. The solar day in Varanasi runs about 23 minutes earlier than in New Delhi, and every Rahu Kaal and Choghadiya boundary shifts with it. For casual purposes the gap is small; for choosing a muhurat it is large enough to matter.
Because it is not a fixed clock time — it is one-eighth of the daylight span, measured from that morning's sunrise. Daylight in Varanasi varies by about 3h 09m across the year, so both the start time and the length of Rahu Kaal move with it.
No. Rahu Kaal, Choghadiya and the panchang are properties of place and date — identical for everyone in Varanasi on a given day. A muhurat chosen against your own chart is a separate question and needs your birth details.