#!/usr/bin/perl -w
use strict;
use Benchmark;
my $now = 8; # we'll pretend it's between 8 and 9 PM
my %url = (
  monday => {
    @{[map(($_,1), (1..1000))]}
  }
);
timethese(100000, {
  a => q{
    $now = (sort grep {$_ <= $now} keys %{$url{'monday'}})[-1];
  },
  b => q{
    $now = ($now < $_ && $_ < 8 ? $_ : $now) for keys %{$url{'monday'}};
  }
});