Answer:
By Moon or by Sun, I shall be found. Yet I am undone, if there's no light around
At night I come without being fetched. By day I am lost without being stolen.
What can run but canβt walk?
I turn around once. What is out will not get in. I turn around again. What is in will not get out.
What is it that no man ever yet did see, which never was, but always is to be?
If itβs information you seek, come and see me. If itβs pairs of letters you need, I have consecutively three. What am I?