$ perldoc -f stat |grep -i time
       $atime,$mtime,$ctime,$blksize,$blocks)
  8 atime    last access time in seconds since the epoch
  9 mtime    last modify time in seconds since the epoch
 10 ctime    inode change time in seconds since the epoch (*)
Notably, the ctime field is non-portable. In particular, you
cannot expect it to be a "creation time"; see "Files and
    printf "File is %s, size is %s, perm %04o, mtime %s\n",
           scalar localtime $sb->mtime;
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compare date time -> perlfaq4 -> How can I compare two dates and find the difference?, How can I take a string and turn it into epoch seconds?