What's the plural form of time dilatation? Here's the word you're looking for.
Answer
The noun time dilatation can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be time dilatation.
However, in more specific contexts, the plural form can also be time dilatations e.g. in reference to various types of time dilatations
or a collection of time dilatations.