Yes, your use of Time::localtime is the key. It overrides the built-in localtime. If you use the built-in, it returns a ctime(3) like string. But in either case, a ctime string isn't going to give you that 2004111622 format in most cases. To get a specific date format, you'd also want to incorporate something like a call to the POSIX strftime function.

I can't tell for sure, but it looks like you may also be trying to stat the base file name only: since you open the directory, you'd need to prepend the directory. Otherwise it will only work if you run it from that directory.