That is when the draws for the second and third qualifying rounds for the Champions League will be made and Celtic will find out the first couple of teams that stand between them and a place in the lucrative group stages.
We all know how important the Champions League is for Celtic, and what an achievement it was to get past Cliftonville, Elfsborg and Karagandy last season.
And Ronny will be well aware of what is at stake when he takes charge of the team for the first time in the competition next month.
There are no easy games at this level, but some ties are less tough than others and Celtic will be hoping for a decent draw when the balls come out of the hat in Nyon.
Obviously, being seeded does help but there are no teams that can be taken for granted and while you might get a club you see as inferior, they may be further through their season than you and therefore sharper and fitter.
You would imagine Celtic should be able to get through the second qualifying round without any major problems, though. One of the big things to consider at this stage of the competition is the travelling.
The trip to Karagandy last season wasn't easy and Celtic left themselves with a lot to do in the second leg after losing 2-0 in Kazakhstan.
The less you have to travel, the better it is for the team.
The first two games against Cliftonhill and Elfsborg were fine and didn't create too many problems for Neil Lennon's side and Ronny will be hoping for a favourable journey early on again.
The travel can affect you and you don't want to have too tricky a trip at this stage of your season, especially if you have to face a team that is fitter and have played more games than you.
We know Ronny doesn't have a lot of experience of European football, he has only been in charge of a couple of games at this level at Stromsgodset.
But the positive thing for him is that he has a group of players who know what it is about and many of them have played in the group stages on a couple of occasions now.
That experience will certainly stand them in good stead as they look to progress through the rounds.
I was at the Karagandy game at Parkhead last season and it was a great night for the club and players.
The Kazakhs certainly weren't the best team Celtic have ever beaten in Europe but it was a huge result and meant so much.
There are still a couple of qualifying rounds to negotiate before they can think about the play-offs and what it will take to reach the group stage.
But that night showed how important it is for Celtic to make it through and join the top teams in the competition and there can be no slip-ups over the next few weeks.
Having only been in the job a few days and only spoken to a handful of the squad so far, Ronny will have to work fast when the squad return for pre-season training next week.
He won't have a lot of time to get his message across but there is no need to change too much too quickly.
There will be things he wants to tweak here and there, of course, but, in terms of the passing style and game he wants to play, the team are already well accustomed to that thanks to Neil. He will be watching footage of games from last year and getting to know the players.
And I am sure he will be speaking to people who have seen more of Celtic in action than him, including his new assistant John Collins.
It won't take him long to realise, which I am sure he has done already, that he has a good squad of players.
There will be things Ronny will want to change, players he will want to move on and ones he will look to bring in.
But the vital thing is that they hit the ground running in terms of results.
It would be great to play the same attacking brand of football right from the off next season, but it is all about getting through these first two qualifiers.
There is no need for drastic changes from last season, this is a squad that has won three titles on the bounce and made the group stages of the Champions League two years in a row. Whether a new manager had come in this summer or not, the whole transfer policy hinges on money from Europe. Do you wait until you have qualified until you make additions to the squad?
Or do you make those additions before and hope that they can see you through?
Celtic are caught in a quandary in that regard, but the one thing they can't afford to do is make changes for the sake of it, that isn't necessary.
And you can't run the risk of being out of the Champions League early doors before the season really kicks off.