Age groups are determined by your age on 7/31 of the current year: 

If you are 5 or 6 on 7/31 of this year, you will be in T-ball
Games and practices can be held on Tuesday, Thursday, and Saturday

If you are 7 or 8 on 7/31 of this year, you will be in Coach Pitch
Games and practices can be held on Monday, Wednesday, and Saturday

If you are 9 or 10 on 7/31 of this year, you will be in Junior F. (this is kid pitch)
Ganes and practices can be held on Tuesday, Thursday, and Saturday

If you are 11 or 12 on 7/31 of this year, you will be in F League
Games and practices can be held on Monday, Wednesday, and Saturday

If you are 13, 14, or 15 on 7/31 of this year, you will be in E League
Games and practices can be held on Monday, Tuesday, Thursday, and Saturday

If you are 16, 17, or 18 on 7/31 of this year, you will be in Senior League
If you are 19 and a graduating senior in the current year, you are still eligible to play in Senior League. 
Gamers and practices can be held on Wednesday and Sunday.