I backup manually, because batch file cannot do what I want (Or maybe I don't know how to do it).
I like to backup every instances of a save file every time I do the save process and keep them all.
For example last week I played and saved, say, ouendan. I add the date of the backup -> 0083 - osu! tatake! ouendan!(2007 07 20).sav
I played the game, and today I backup the save again -> 0083 - osu! tatake! ouendan!(2007 08 05).sav
If, for some reason (that already happened a lot with my G6), the last save file is corrupted, I still have save game working and I don't need to play the game again from the beginning.
I had ouendan1, megamanZX, mario & luigi (gba), etc. corrupted, this helped me.
So, I would like a batch process to check the "last change" date of the file, and check if the "filename+date" file already exist on the computer, if not then save and append it with the last changed date, else check next file.
maybe doing it in C or PHP if I have time.
Meanwhile, I'll do it manually, it's still the best.