I have a series of 300+ files that I need to sort twice, once by the date and a second time within that date by part of the filename.The only standard in the names is that ends with *mmddyyyy<time stamp>.csv, where the first part of the file name can include anything at all.  I know ls -ltr gives me the date sort but I can't seem to capture and sort on a portion of the last keydef.
sort files twice
shell script;sort