use strict;
use utf8;

open(FILE, '<C:/Users/li/perl/part1.txt') || die "File not found";
my @lines = <FILE>;
close(FILE);

my @newlines;
foreach(@lines) {
   $_ =~ s/([\d]{10})/localtime $1/eg;
   push(@newlines,$_);
}

open(FILE, '>C:/Users/li/perl/part1_CORRECTED.txt') || die "File not found";
print FILE @newlines;
close(FILE);