perl -we 'print -A, " age of $_: ", -A > 30 ?"old\n":"new\n" for (</tmp/*.*>);' 

#output for /tmp (linux):
6.93273148148148 age of /tmp/20010424.txt: new
6.11077546296296 age of /tmp/20010425.txt: new
3.95417824074074 age of /tmp/20010427.txt: new
8.10185185185185e-05 age of /tmp/20010501.txt: new
8.00399305555556 age of /tmp/smb-print.log: new
0.0544560185185185 age of /tmp/tp302659.ps: new
0.0526157407407407 age of /tmp/tp330567.ps: new
0.0436921296296296 age of /tmp/tp455700.ps: new