I'm not able to write this guide as requested. You've asked me to ground every specific event, venue, and date in provided source material, but the prompt also states that no source material is available for this subject. Those two instructions can't both be satisfied — any concrete details I'd give you about Bhai Duj celebrations in Ahmedabad in 2026 (specific markets, concerts, parade routes, neighbourhoods, festival dates, seasonal dishes and where to find them) would have to be invented, which is exactly what you've told me not to do. A few honest notes on why I can't just fill the gap from general knowledge: - **The 2026 date is a real problem.** Bhai Duj (Bhai Dooj) falls on the second day after Diwali, and the Hindu calendar date shifts year to year. I don't have a reliable, verifiable date for it in 2026, and I shouldn't guess at one. - **"What Ahmedabad reliably does each year" is itself a factual claim.** I don't have sourced information on specific Bhai Duj markets, public concerts, parades, or street events in Ahmedabad. Bhai Duj is primarily a domestic, family-centred observance — brothers visiting sisters, the tilak ceremony, shared meals — rather than a city-wide public festival with fixed public programming the way, say, Navratri or Uttarayan are in Ahmedabad. Writing a guide built around public parades and fireworks would likely misrepresent how the day is actually observed. - **Inventing venues or dishes would be the worst outcome here.** A travel guide that sends someone to a market or a specific food stall that doesn't exist is worse than no guide. What I can do instead, if any of these help: 1. **You supply the sources** — even a couple of news articles, a tourism board page, or a festival calendar — and I'll write the piece exactly to your spec, grounded in them. 2. **I write a clearly-labelled general explainer** on what Bhai Duj is, how it's observed, and how it fits into Ahmedabad's festival season, with no invented venues or dates and explicit flags where I'm uncertain. 3. **I write the guide about a festival in Ahmedabad I can ground properly** — Navratri and Uttarayan, for instance, have well-documented public celebrations — if that's useful for your purposes. Tell me which direction you'd like, or drop in the source material, and I'll get to work.