Minister for Housing and Local Government James Browne has signed the polling day order for the Dublin Central and Galway West bye-elections.
Mr Browne signed the document at the Department of Housing offices in Wexford town this morning.
The document officially appoints Friday, 22 May as the polling day for the two bye-elections.
Polling stations will be open from 7am until 10pm on that day.
The latest time for receipt of nominations from prospective candidates is 12 noon on Friday 1 May.
Candidates may withdraw their nominations up to 12 noon on Saturday, 2 May.
A person eligible to vote but not yet registered can submit a completed application to the registration authority for the area in which they reside by Tuesday, 5 May.
The deadline for receipt of applications for postal and special votes is Saturday, 25 April.
The electorate for the Dublin Central constituency is currently over 57,000, while the electorate for the Galway West constituency is currently over 103,000.
Speaking after signing the polling order, Mr Browne encouraged people to exercise their democratic right in the upcoming bye-elections.
He said: "I think it's really important that people do go out to vote on 22 May, we have one of the longest continuing democracies in the world.
"It's really important to protect that and we have a participatory democracy so I would encourage people to engage with the candidates, engage with their policies, and to go out and vote on the 22nd.
"If they need further information, they can go online and check out An Coimisiún Toghcháin," he added.
In the Dáil last night, Fine Gael's Emer Currie moved the Dublin Central writ for the bye-election to fill the vacancy created by the departure of former Minister for Finance Paschal Donohoe.
The second vacancy in Galway West arises from Catherine Connolly's election as President of Ireland last year. After moving the writ for Galway West, People Before TD Richard Boyd Barret said "get the posters up".
Government parties have a poor record in bye-elections and so Opposition parties and Independents will seek to make gains. However, the results would not significantly alter the Government's Dáil majority.
Read more:
Bye-election writs moved, voting set to take place 22 May
Dublin Central constituency profile
Galway West constituency profile