If the files were created on set dates you can just sort them by date in explorer. I'm guessing this is not the case. So if you rename files as Molly suggested (yyyy-mm-dd) then sorting by name will also sort them by date.
Since you already have a bunch of such files instead of renaming them one by one, I suggest you use Total commander, which has built in multi-rename tool. This tool enables you to easily rename files to this format. Just rename each batch of files that have same type of name after another.
To rename for example files named dd-mm-yyyy to yyyy-mm-dd:
- select files you want to rename (using either r-mouse click or space)
- press ctrl+M or select menu Files -> Multi rename tool
- press Range button and select year part, press ok
- repeat for month and day and put - in between, you should end up with [N7-10]-[N4-5]-[N1-2]
- press Start button (bottom of the form) to run the renaming process
- repeat the process for other groups with similar names