Defending champions Harlequins will launch the new Aviva Premiership season at Twickenham on September 1.
Quins return to scene of their Premiership final triumph over Leicester more than two months ago when they tackle Wasps.
It will be the first half of English rugby's now traditional opening weekend London double-header at Twickenham, with Saracens facing London Irish later the same afternoon.
Premiership newcomers London Welsh's opening fixture at their new Kassam Stadium home in Oxford is against Leicester on September 2, with a 2pm kick-off.
League organisers confirmed dates and kick-off times for the first eight rounds of Premiership fixtures.
Saracens' second home league game - against Leicester on September 15 - will be held at Wembley Stadium, while Sale Sharks' first fixture at Salford City Stadium is the previous weekend against Saracens.
And since the original fixtures were announced earlier this month, London Welsh and Saracens have agreed to swap venues of their games, which means the Exiles hosting Saracens on October 7 and then playing the return encounter on March 3.