League Survivor is going on for the first time!

Rules regarding games
The groups S, A, B, C, D, E, F, and G will each do a round-robin tournament.
The boot time starts at two days for Group S and goes up by 12 hours for each lower group.
Vacations are dishonored, meaning if you take a 3-day vacation in the highest two groups, it will guarantee your booting.
The cycle until Group F for fog goes as follows: Normal, Light, None.
For Group F and lower, it starts at Light Fog.
It starts at 0 for S through B, 3 for C through E, and 5 for F and G for starting income before bonuses.

Rules regarding starting placements
If your level is 30 or higher, you will start in group C. If it is 29 or lower, you will start in group D.

Rules regarding the promotion/relegation system
At the end of each round, the top half (determined by placement) for even player groups will get promoted, but the other half will get relegated.
If a player gets relegated from Group G, they will get eliminated.
For odd player groups, the median player will have a 50% chance of being promoted, and a 50% chance of being relegated.

How many groups are there?
Eight, of course, since the starting groups depend solely on your level.