Is there any way, that I can reduce the amount of photos.
I have over 65.000 photos taken over 2 days, and clearly I had the interval all wrong.

I have tried the Long Term Worflow, but it doesn't seem to fit the purpose, as it filters on different parameters.

What i really want to do is use only every 10th or 15th photo for the timelapse.

Kind regards
Anders

You can load the whole sequence into LRTimelapse, and then use the "Select every nth" photo feature from the edit menu.
So let's say you select every 10th photo. Then Edit/Invert selection.
Now right click on one of the selected photos and choose "New folder from selection" - this will move the unwanted photos to another folder. If you want to delete them, you could also choose "delete photos" instead.

Aha, great thank you that was exactly what I was looking for.