Nikon 5100: predawn to daylight time lapse. How do I focus the lens?

Obviously, in pitch darkness, neither the camera nor I can focus the lens.

I can focus in daylight the day before, but fiddling the lens cap generally messes that up.

I just want it focused at infinity. Why does the lens go beyond that? Grumble.

You will need to over ride the auto-focus feature. Simply set the A/M switch on the lens to Manual. Focus for infinity and then proceed with the rest of your plan.

You could try focusing on some distant streetlight, or maybe point car headlights at something distant enough to give a decent infinity focus. Do some practice shots with this before investing many hours on your project.

During daylight, focus and look at the result. Chances are the lens is focused just a teeny bit short of all the way since yes, there's this odd point "past infinity".

Since you'll probably want to use a fairly small aperture, you'll have plenty of DOF to get right, anyway.

To manually focus your lens to infinity, put the lens into manual, then go to infinity focus on the lens (until it hits the focus stop). Then back off just a bit.

Backing off is necessary otherwise you will have DoF compression. DoF occurs both in front of and behind the true focus point. So if you focus the lens to infinity, the behind focus point DoF is lost.

But if you bring the lens back just a bit, then the behind DoF focus point (hopefully) will be at infinity, and the front of focus DoF point will hopefully be a bit more forward. This gives you maximum DoF.