Little league has strict rules to ensure fairness of play regarding player-age.  Upon registration every parent/guardian needs to upload the players birth certificate, if they haven't already done so in years past. 

For baseball the player age increases on Sept 1st.  This means your child might be 8 years old, but for little league purposes s/he is player-age 9.  Every year little league posts a player-age table for the current year. 

For Baseball you can find the 2025 chart here.
For Softball the player age increases on Jan 1st.  You can find the 2025 chart here.