Just to clarify the idea of where your Day Hike permit is required: You can hike ANY time up to Lone Pine Lake, and without a permit.
It is only after Lone Pine Lake that the Day Hike permit is required.
This issue comes up from time to time, and I have verified with Inyo staff in Bishop: You only need the Day Hike permit starting at LP Lake. It is NOT required below that point. So you can legally start your day hike before midnight.
However, an overnight wilderness permit IS required, starting at the trail head, if you carry overnight gear up to Lone Pine lake, since you would be camping there (or somewhere beyond). You cannot camp at Lone Pine lake (or anywhere else along the trail) without an overnight wilderness permit -- the same permit as required to camp anywhere on the main trail. ...and therefore, I suppose an overnight trip cannot start before midnight. But who would want to?
