Thank you for your replies.
I see where I didn't make myself clear: I want to animate the shader properties of the built in "Procedural Skybox". On a regular shader, you can animate the properties as you would animate anything else, but with the Procedural Skybox, it's not possible, since it's not attached to any object, but assigned in the lighting panel.
Some of the properties I want to animate is the Sky Tint(color) and Exposure(float).
I can ease the color and float using Playmaker actions, that works fine, but I don't want to ease float, I want to animate it using keyframes in the Animation Window. It's the same result visually, but I need the keyframes in order to preview in the Timeline. Timeline previews animation, but not logic.
I hope it's more clear now