What is a good duration time for UI animations?

To minimize initial cognitive load, we plan to hide dependent fields within our software by adding animation to show / hide them when called.

I have been looking for articles on duration timing on animation and have not had much luck.

Does anyone have experience with this, or has anyone done any user testing on this?

Here is a link to the animation we are going to be using set at 300ms:

https://www.screencast.com/t/RKuMb97o