No Pro14 derbies will be played on Boxing Day, New Year's Eve or New Year's Day in the 2018-19 season.
Instead of games held on Boxing Day, traditional holiday derbies between the Welsh, Irish, Scottish and Italian sides will be held on 22 December.
The change aims to give players more recovery time between matches.
Festive games will also be played on 29 and 30 December and 5 January, with some of those screened free to air by Welsh-language broadcaster S4C.
European Challenge Cup holders Cardiff Blues host Pro14 champions Leinster on Friday, 31 August, the opening weekend of the 2018-19 season.
Ospreys host Edinburgh the same evening, while Scarlets are at Ulster on Saturday 1 September and Dragons host Benetton later that evening.
The first meeting between two Welsh sides is scheduled for Saturday, 6 October when Ospreys travel to take on Scarlets while Blues go to Rodney Parade to take on Dragons.
The fixtures from that weekend are reversed for 22 December, which sparks three consecutive weekends of Welsh derby games.
The following weekend Dragons host Ospreys before Blues go to Scarlets, then on 5 January Blues are on the road again when they go to Ospreys while Scarlets welcome Dragons.
The final meeting of the season between Welsh sides is scheduled for the weekend beginning 22 March, with Blues v Scarlets and Ospreys v Dragons likely to take place at the Principality Stadium as the seventh annual 'Judgement Day' double-header.
Pro14 tournament director David Jordan said: "For the first time we have produced fixtures with kick-off times and dates right up to Round 17, which we have never been able to do before.
"When you consider the planning required around incoming and outbound South African tours, it's fantastic to have so much of the season mapped out ahead of us at this point.
"Rarely, has there been so much anticipation and excitement ahead of a new season now that we every game live across the UK on Premier Sports fully supported by eir Sport and TG4 in Ireland, Super Sport in South Africa and S4C in Wales."
The knock-out stage Play-offs will take place on the weekend of 3 May, with the semi-finals on 17 May and the final on Saturday, 25 May which is expected to be played at Celtic Park in Glasgow.
The Pro14 will again be split into two conferences of seven teams - which remain unchanged from last season - with the top three sides from each conference qualifying for the knock-out stage.
The four sides finishing second and third in their respective conferences will contest the quarter-finals in cross-conference games, with the conference winners getting a bye to the semi-finals where they will have home advantage.