You would think there were a function in Linux already that would do this. The following command will sort all files in a directory and all subdirectories for the past 14 days by datestamp.
bash$ find . -mtime -14 -type f | while read line; do echo -n `ls -l --time-style='+%s %F %T' "$line" | awk '{print $6,$7,$8}'`; echo " $line"; done | sort | cut -d ' ' -f 1 --complement
