The millennium celebrations will have a novel opening in Co Westmeath, where in a private ceremony a beacon will be lit on the Hill of Uisneach, near Mullingar, which was the home of the kings of Ireland before Tara.
The beacon will signal the start of the festivities in Westmeath, with the symbolic Last Lights ceremony at the Arts Centre, Mullingar, and the Castle, Athlone.
There will be similar ceremonies in Moate and Kilbeggan, and at all the locations local bands will provide music for the event.
The Last Lights ceremony will be held in the Market Square, Tullamore, beginning at 4 p.m., where the Mountbolus Pipe Band and the Brady family will provide music until 4.30 p.m.
At 4.30 there will be an address by the chairman of Offaly County Council, Mr Eamon Dooley, who will raise the millennium flag to a recital of music by the Messiah 2000 Youth Choir. Following the lighting of the Millennium Candle, there will be interdenominational prayers.
The Market Square ceremony will conclude with a mime group leading the audience to the Church of the Assumption for an ecumenical service.
In Portlaoise, the ceremonies will begin at 11.30 a.m. with the planting of a tree at Millview Park by the chairman of the county council, Mr Joe Dunne.
The Lights ceremonies will take place in Portarlington, Luggacurren, Stradbally and in Castletown, where the local Foroige club will bury a time capsule, to be opened in 50 years.
Ceremonies will begin at 4 p.m. in Killeshin, Durrow, Rathdowney, Camross, Cullohill, Abbeyleix and Portarlington.
The Lights ceremony will begin in Longford at 4 p.m., with music and song on the streets until 5 p.m., when there will be an interdenominational ceremony.
Street entertainments and other events will be held in Abbeyshrule, Ballymahon, Kenagh, Granard and Dromard, where local people have arranged a video link-up with exiles in London, the US and other parts of the world.
There will be a strong emphasis in the midlands on religious ceremonies.
In the diocese of Meath, three places have been designated as pilgrimage sites where special Jubilee indulgences may be obtained. They are the Cathedral of Christ the King in Mullingar, which will be the focus of special ceremonies on the last night of the millennium, Slane's parish church, and Clonard, because of its association with St Finian, the patron saint of the diocese.