Keng

This is bash shell to clear file create by time with 60 m * 8 hour = 480 m :

 #!/bin/bash  

 homedir=( folderName1  
 folderName2  
 folderName3  
 folderName4  
  )  

 for d in ${homedir[@]}  
 do  
     echo "Homedir: /var/nginx/cached/$d"  
     find "/var/nginx/cached/$d" -type f -amin +480 -exec rm {} \;  
 done