Connacht, with new head coach Pat Lam in place, will be at home to Zebre in the opening round, with Munster also opening their league challenge with a home fixture - they entertain Edinburgh first up.
Glasgow Warriors, the remaining team to make it through to last season's play-offs, also face Welsh opposition, but this time the Cardiff Blues will have to make the journey north to Scotstoun Stadium.
There are the regular local derby fixtures to look forward to over the festive period, while the final round of the regular season, round 22, is scheduled for May 9-11.
The semi-finals follow a week later and the 2013/14 PRO12 season concludes with the final on the last weekend in May.
Tournament director David Jordan commented: "It is ten years since the competition changed to a home and away format and four years since the introduction of the end of season play-offs.
"During that time a regular season pattern has emerged and we have seen increases in both attendances and viewing figures so fans are obviously enjoying the rugby that is on offer in the RaboDirect PRO12.
"In the coming season fans in the home Unions have the added excitement of the victorious British & Irish Lions players returning to their clubs to look forward to as well.
"Since the inception of the competition five different teams have taken the title, although interestingly no champions have ever defended their crown - Leinster will have a challenge on their hands in the coming season."
2013/14 RABODIRECT PRO12 OPENING FIXTURES:
Round 1 - September 6/7/8
Benetton Treviso v Ospreys
Glasgow Warriors v Cardiff Blues
Munster v Edinburgh
Newport Gwent Dragons v Ulster
Scarlets v Leinster
Round 2 - September 13/14/15
Cardiff Blues v Connacht
Edinburgh v Newport Gwent Dragons
Leinster v Ospreys
Scarlets v Benetton Treviso
Ulster v Glasgow Warriors
Zebre v Munster
For a full list of the 2013/14 league fixtures, please click here.