Eid was celebrated in Trafalgar Square on 20th Oct Liz, Diwali was celebrated with a festival of light on 28th October

OK - maybe London was celebrating a little early as officially Diwali (although Oct 21st last year) doesn't start this year until Nov 9th - but I suppose festivals based on lunar cycles are a little more difficult to organize at a different time each year on that kind of scale.