http://www.rozhlas.cz/vltava/program/

vltava.pl

use v5.10;
use strict;
use warnings;
use open qw/:std :utf8/;
use JSON::PP;

# API call example
# http://api.rozhlas.cz/data/v2/schedule/day/2017/01/05/vltava/brief.json?callback=jQuery18204554739051964134_1484244887343&_=1484244901325

# *.json
my @dny = @ARGV;

for (sort @dny) {
    @ARGV = $_;

    # skip the first line
    # // data wrapped in a function call
    <>;
    
    # print JSON::PP->new->pretty->encode( decode_json(substr(<>,0,-3)) );

    my @porady;
                                # remove last 3 characters
                                # // data wrapped in a function call
    for my $porad (@{ decode_json( substr(<>, 0, -3) )->{data} }) {
        # 2016-12-29T00:00:14+01:00
        my $hodina = substr((split("T", $porad->{since}))[1], 0, 2);

        # between 10 p.m. and 4 a.m.
        if ($hodina < 4 or $hodina > 21) {
            push @porady, qq($porad->{since} $porad->{title});
        }
    }

    say join "\n", @porady;
    
    # wait
    <STDIN>;
}