#!/usr/bin/perl

use strict;
use warnings;

use LWP::UserAgent;

# Modify the args as needed for your locale
my $URI = 'http://www.time.gov/timezone.cgi?Eastern/d/-5';

MAIN:
{
    # Create user agent
    my $ua = LWP::UserAgent->new;

    # Create request
    my $req = HTTP::Request->new(GET => $URI);

    # Get remote time, and monitor local (computer) time
    my ($res, $t1, $t2);
    do {
        # Get local time
        $t1 = time();
        # Execute request
        $res = $ua->request($req);
        # Read local time again
        $t2 = time();
        # Loop if the two measures of local time differ
    } while ($t1 != $t2);

    # Check response
    if ($res->is_success) {
        # Extract remote time
        my ($hh, $mm, $ss) = $res->content =~ />(\d{1,2}):(\d{2}):(\d{2})</;
        if (defined($ss)) {
            # Output remote time
            printf("Remote time: %02d:%02d:%02d\n", $hh, $mm, $ss);
            # If local and remote times differ, then output local time as well
            if ($ss != $t1 % 60) {
                ($ss, $mm, $hh) = (localtime($t1))[0-2];
                printf("Local time : %02d:%02d:%02d\n", $hh, $mm, $ss);
            }
        } else {
            print("ERROR: Time not found in returned results.\n");
        }
    } else {
        print('ERROR: ', $res->status_line, "\n");
    }
}

exit(0);

# EOF