See http://www.environ.ie/en/LocalGovernment/Voting/News/MainBody,5103,en.htm (here) 0730 to 2230 It seems.
Mr. Dick Roche, T.D., Minister for the Environment, Heritage and Local Government, has today (30th April 2007) made an order appointing Thursday 24th May 2007 as polling day and the hours from 7.30am to 10.30pm to be the hours of polling at the General Election to be held as a consequence of the proclamation issued on the 29th April 2007 dissolving Dáil Éireann.