Monday 3 Jan New Year*
Friday 22 Apr Easter
Monday 25 Apr Easter
Monday 2 May Monday 2 May*
Monday 30 May Spring*
Monday 29 Aug Summer*
Monday 26 Dec Christmas*
Tuesday 27 Dec Christmas*
On Friday 23 December and Friday 30 December 2011 all Exchange markets will close from 12:30 London time onwards.
Source: http://www.londonstockexchange.com/about-the-exchange/company- overview/business-days/business-days.htm