What start date would work?

I wanted to make a start date in July so that I can manage in the Olympics. The problem is that I believe the game would only accept certain dates. I have tried to make one starting on a Monday but that still doesn't work. Anyone knows what stat date is valid?   

The problem is that you would have to change every single rule to the new years date. 3 things you can do:
1. Load the Brazilian league as late as possible so you could start in December.
2. Create a lower league with all the rules on your new date and load that in game
3. Edit every single rule of an existing league to your new date. I believe the South African league has the least rules if you want to do this.
Theres some help here and here if you wanted to give it a go. I would recommend option 2.

Thanks. I didn't realize that custom starts need to adhere to the rule of the league.