Trading holiday on Thu, April 24 due to elections in Mumbai, F&O expiry on April 23rd now. Updated on the calendar: http://zerodha.com/z-connect/traders-zone/holidays/trading-holidays-2014-nse-bse-mcx
https://zerodha.com/marketintel/Circulars/5483
https://zerodha.com/marketintel/Circulars/5483