Ireland, Triple Crown winners last season, must travel to Wales for their first game of the 2007 championship and face heavyweights France and England in successive rounds.
Both games - Ireland's only home fixtures - will be staged at the 82,000 capacity Croke Park with Lansdowne Road set to undergo redevelopment at the end of the year.
The climax of Scotland's Six Nations is a clash with Les Bleus at Stade de France while Wales travel to Paris on February 24, with all three matches in round four taking place on the Saturday.
England's meeting with France on Sunday March 11 could be instrumental in determining the 2007 winners, although the world champions will need to produce a vast improvement on this season's showing.
But if Wales rediscover the form which secured the Grand Slam last season - and are dealt a kinder hand on the injury front - their trip to Twickenham could become the decisive match.
Scotland head coach Frank Hadden has welcomed an all-Saturday tournament for his team ahead of the World Cup in France.
He said: "I'm pleased that our matches fall on Saturdays. That makes our preparation much easier.
"I'm also pleased for the supporters because I know how important it is for those travelling to support Scotland, whether away or at Murrayfield, to have the games on a Saturday.
"Our schedule for 2007 should make it a special occasion for the supporters wherever we're playing.
"These matches are part of rugby's 'jewel in the crown' but they're also part of our build-up for next year's World Cup.
"That build-up begins on May 31 (this year) when we welcome the Barbarians to Murrayfield."