If I download this clip with youtube-dl, the last modified date is 15 November 2018 03:55, while YouTube shows a posted date of 23 April 2013. This page mentions that one cannot replace a video:
You can’t replace a video since any new video uploads will get a new URL
I would like to change that date to the date of the download, i.e. today, instead of that other date. The downloader launches asynchronously, so I can't easily pipe the filepath to touch. I have not found any option in the documentation. If I can't find any good solution, I will look at the Python source code and submit a pull request.
What is that date, and can I easily set the modified date to today?