Future Six Nations could start two weeks later in the season to help reshape the global calendar, according to tournament chief executive John Feehan.
Rugby bosses around the world are still thrashing out the international schedule to run after the 2019 World Cup, and Six Nations chiefs have admitted they would be relaxed about their competition starting later.
This year's Six Nations kicks off on the first weekend of February but from 2020 the tournament could start two weeks later within the same month.
"If the start date is pushed back to start in the middle of February, that's okay, it's no big deal there," said Feehan.
"If for whatever reason it makes sense for the Six Nations to start two weeks later than it does now, that's fine. It's no big deal.
"It's fair to say that on balance, when it's been looked at and particularly player welfare and all that kind of thing, you can't bring it down below seven weeks because the guys can't perform at that level five weeks on the trot.
"It's particularly unfair on the smaller nations, England and France might have the resources to do that but others don't.
"The reality is we need to keep the integrity of the tournament right and so we need to have the rest weeks to do that."
'We're very happy with bonus points'
The Six Nations trialled losing and try-bonus points for the first time last season and Feehan has confirmed they are here to stay.
"Overall, we're very happy with bonus points; I wouldn't want to overstate it but on balance it's had a positive net effect," he said.
"That's more in the psyche than anything else. It's very hard to give you empirical evidence that it's better. But we believe overall, on balance, that it was a good decision and we're going to keep it.
"It certainly didn't take away from anything. It's hard from the evidence to say it had a massive effect, but we think it's positive.
"It's a very evenly-matched tournament this year and we think the bonus points may have more of an impact this time.
"We're going to keep it in situ, it's now part of the championship, we're going to stick with it."