How to Measure Shader Performance without Profiler?

Hi, Is there a way to measure how long a Shader takes to perform a certain action, e.g. apply color or add 100000 times? And trying to do that without any external tools (Unity Profiler and such)

What I am trying to do right now is to get _Time.y difference between when a function starts and ends, but I don't know how to pull that information from Shader to C#. Is there a way to do that? In fact, is that even something that makes sense for what I am trying to do? Thank you!

Would really appreciate examples and/or suggestions.