Haha, of course, I wouldn’t suggest using YYMMDD for an institutional library, historical archive, or any other transcendental venture.
But for a mere living creature that will be creating content only during the XXI century (like I am), I find the 6-digit prefix much more useful than wasting all 10 characters just for the date prefix on the little space for a file name.
Of course, this is a very personal choice. I did it mostly because when searching on my saturated archive, a 10 character prefix uses mostly all the name preview space and I cannot read the more important data that comes after the prefix!
I think I just weighted what is more critical in my organizational system and found out that gaining 4 characters gives me more advantages than the possibility of someday having to file something with a different century than XXI, which as I only use this system to file and archive my artwork and content production, I will never need to use a different first two digits than “20” if I used the YYYYMMDD.
You might think, that just 4 digits difference is not that big of a deal, but being a multidisciplinary artist I also use some other prefixes to indicate Area, Discipline, Platform, (along with creation date of course) so every character gained on the file naming counts a lot for me if I want to keep those file names readable!
I repeat (just in case) that this is not optimal but is what works best for me considering I had to give up some benefit in order to achieve a more legible archive. But I don’t mean this to be a standard, I was asking other opinions here to see if other “single-century” creators found this 4-digit prefix date is an advantage on their systems, too. Organizational systems might be a constant work of improvement, so it is nice to know other approaches, too