The Irish Stock Exchange is to open on three public holidays this year as part of a move by European stock markets to harmonise their trading calendars. As well as being open on the St Patrick's Day holiday last Monday for the first time, the Irish Stock Exchange will also be open on the August and October bank holidays, August 6th and October 29th. The Irish Times was not made aware by the Irish Stock Exchange that March 19th was a trading day and, as a result, no Irish share prices were published in yesterday's newspaper.