Alter aging

You touch a creature that isn't dead or has an infinite lifespan. This spell lasts until it's dispelled with the "Dispel Magic" spell for the 0.8 times faster effect or "Remove Curse" spell for the 3 times  faster effect respectively.

You alter their bodily aging process by making them age 0.8 times or 3 times faster. This effect doesn't affect the mind 

An unwilling creature can make a Constitution saving throw and if it succeeds, it isn’t affected by this spell.

At Higher Levels. When you cast this spell using a spell slot of the 5th level or higher,  the basic effect gets multiplied by 0.8 (4/5) or 3 for each slot level above 4th respectively. Quick overlook: 5th level 0.64 (~2/3) or 9 times. 6th level 0.512 (~1/2) or 27 times. 7th level 0.4096 (~2/5) or 81 times. 8th level 0.32768 (~1/3) or 243 times. 9th level 0.262144 (~1/4) or 729 times.