An armchair guide to the election count
10 constituencies to keep an eye on
Galway West: Michael D Higgins's home patch and also Dana's base. The Labour candidate will expect a big boost from his home crowd.
Louth: Sean Gallagher's base and Gerry Adams's constituency. The Gallagher and Martin McGuinness figures will be interesting.
Tipperary North: The weather-vane constituency in a general election and always a good barometer for how the nation votes.
Mayo: Taoiseach Enda Kenny's turf where Fine Gael won an historic four seats in the general election. Kenny's under pressure to deliver.
Dublin Central: David Norris's base and also the home of Labour director of elections Joe Costello.
Dublin South-Central: Gay Mitchell's home turf which he has represented for 30 years, so he'll be expected to poll heavily.
Dublin North-East: Mary Davis's home base, but also dominated by the Labour Party and Fine Gael in the general election.
Cork South-West: Michael Collins country where Fine Gael is dominant. Where that support goes will be intriguing.
Dun Laoghaire: Tanaiste Eamon Gilmore's constituency and regularly a spot that goes heavily with the national swing.
Cavan-Monaghan: Sean Gallagher's home county, but also a Sinn Fein stronghold.
Timeline of day
9am: Ballot boxes opened in the 43 constituencies and papers sorted, between presidential election and the two referenda. Counting starts.
11am onwards: Tallies expected to give an indication of what way the vote is going.
1pm onwards: The results of the first counts are expected to be transmitted to the count headquarters in Dublin Castle.
5pm to 7pm: Official result of the first count and the quota expected to be declared at Dublin Castle by the national returning officer Riona Ni Fhlanghaile.
Thereafter: Second and subsequent counts until the winner is declared.
Saturday: If the presidential count is not finished, it may spill over into Saturday.