You could do that at any time and for any time period if you'd like:
Then, at a command-line/terminal, navigate to the root folder of the cloned repository and issue a command to start the generation of the video. At this point, I don't see that a GUI is available for this, so it will have to be done at the command line. The command the uploader of the video used is:
gource -s 0.1 --hide filenames --highlight-users --title "Kicad development" -1920x1080 -o - | ffmpeg -y -r 60 -f image2pipe -vcodec ppm -i - -vcodec libx264 -preset ultrafast -pix_fmt yuv420p -crf 1 -threads 0 -bf 0 gource.mp4
Look closely at the command above. Notice the "|" before ffmpeg. The output of gource is being "piped" into ffmpeg to create the video. The last item (gource.mp4) specifies the file name for the final video.