Which of the following is correct?
It has been two hours since I have left LA.
It has been two hours since I left LA.
I know everyone will pick 2 but why one is 1 is not correct as we use present perfect for past events which are relevant to present moment.
It has been two hours since I left LA.
This is the correct one. Because your leaving is not relevant to the present time. You left LA. The action is finished.
It has been two hours because still you are living in this period of time. Even though after 3 years passed you should use:
It has been 3 years since I left LA.