Remove Night from Timelapse Footage

I have about 500 days of timelapse footage of a building site shot as 720p footage I've converted to H264. I need to remove the night time shots leaving only day. I believe it's possible to use FFMPEG to do this automatically as per this link: https://video.stackexchange.com/questions/20881/how-do-i-remove-night-footage-from-300-days-of-time-lapse-video

However,

- I'm not familiar with FFMPEG and
- The timelapse is broken in to 10 video files, the start time will be different for each
- As we go through the seasons the amount that needs to be removed changes - this doens't need to be exact, but I want to roughly get from sunrise to sunset each day

For someone that's done this before, I imagine it will be a few hours work. It will certainly be a lot quicker than doing it manually.

Deliverable is the full video 720p H264.