The Path of the Eternal Turtle

The caster finds a suitably comfortable rock to sit upon on a sunny day, assumes the correct posture, and enters a meditative state. If the caster is able to spend the entire casting time in undisturbed meditation, the spell will complete, and they will not grow any older until the spell's duration ends.

The caster can still be aged magically while under the effect of this spell, however they will not naturally age during the next year. 

A caster will still continue to grow if they have not finished growing yet, and may still show some minor physical signs of growing older, especially if they are of great age.