Let me save you a few characters: %Y-%m-%d can be shortened to %F
For visualisation’s sake I also like to put a space before the %F so that the year and the file size are separated a little more, but that’s more of a taste thing than anything else.
(Caveat: %F’s year is explicitly four digits in some libraries, whereas %Y is always the full year. If you’re planning for your code to last 8000 years you might want to consider that.)




I still backup my files the most basic way, that is, create an archive locally, connect external storage and copy it there. Then disconnect external storage. The archive is made onto a separate internal drive and I keep the most recent one there, so I don’t even need the external one for minor accidents.
I think only once in the last decade or so have I wanted (but never needed) to pull something back from external, but it’s nice to know it’s there.
The main downside to this method is that it doesn’t de-duplicate, so keeping several takes a lot more space that it would do otherwise.