Remove all of the files between hour X and hour Y regardless of their date
# Find the files tha tmeet the criteria
# this is helpful if you want to preview what you will delete
find . -newermt "`date --date="yesterday" +%b" "%d" "%Y" 18:00:00"`" \! -newermt "`date +%b" "%d" "%Y" 07:00:00"`" -exec ls –lart {} \;
# Actually then delete the files
find . -newermt "`date --date="yesterday" +%b" "%d" "%Y" 18:00:00"`" \! -newermt "`date +%b" "%d" "%Y" 07:00:00"`" -exec rm {} \;