The Time Ravage spell (Explorer's Guide to Wildemount, p. 189) states:
The target [takes] 10d12 necrotic damage on a failed save, or half as much damage on a successful one. If the save fails, the target also ages to the point where it has only 30 days left before it dies of old age. In this aged state, the target has disadvantage on attack rolls, ability checks, and saving throws, [...]
In most normal situations this is quite self-explanatory, but what about creatures that age differently (or don't age)? Explicitly:
How would that spell work on creatures that become stronger with passing time, not weaker, or that grow indefinitely? Would a young dragon be transformed into its ancient version, just at the limit of its lifespan, hence the disadvantage on the rolls? What about aboleths, warforged, or others that do not deteriorate with passing time at all? Are they even affected by anything but the damage of the spell? And what about chuul, which are also immortal and grow all their lives?
How would that spell work on creatures that do not age at all? Most planar creatures are impervious to passing time; fiends and celestials and many others do not change at all in regard to passing of time by itself. How would that spell work with them?