Accelerate/Reverse Animal Growth

You begin to accelerate or reverse the age of one beast you can see in range, that has a minimum Intelligence score of 1. The target must make a Charisma saving throw, or have its age increased or decreased by up to six months on a failed save. The age of the beast changes at a rate of 3 months per turn. If the target exceeds their natural lifespan, they die. A creature cannot be made younger than 1/8 of its maximum lifespan, rounded down.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the amount of time you can accelerate/reverse increases by 6 months for each slot above 5th.