[nullserver]

Plank length was found because it fixed equations.

I don’t think any equivalent has been found for time units. Not that can be experimentally proven yet.

Would love to see time proven one way or the other.

[AstralStorm]

Unless you discover time crystals in old sense of the word, everything we know about time is related to momentum, esp. thermal equilibrium and symmetry breaking.

This means it is subject to Planck scale and uncertainty principle.