Timeline timing keyboard shortcuts

I'm looking for keyboard shortcuts to use on the timeline for changing the timing for a layer or layers quickly. I may have a layer set to "show to end" but I want it to stop at 3 seconds rather until the very end. I have seen these types of "timing/timeline" keyboard shortcuts but they are difficult to find. I want to be able to change the timing of a layer using shortcut keys. Another example would be to use a keyboard shortcut to make the layer show until the end. Using a keyboard shortcut would save me from dragging the layer/layers to change the timing. Looking for keyboard shortcuts only, not right-click or menu options.  Thank you!