#!/usr/bin/perl
use strict;
use warnings;

use Astro::Sunrise qw(sun_rise sun_set);

sub tmath {
  my ($time, $offset) = @_;
  
  my ($hour, $minutes) = split(/:/,$time);
  
  $hour += $offset;
  
  return "$hour:$minutes";
}

my $user_lon =  -77.314444;
my $user_lat = 39.534444;

my $user_spot = { lon => $user_lon, lat => $user_lat };

my $noon = '12:00';
my $dawn = sun_rise($user_spot);
my $dusk = sun_set ($user_spot);


my %dayparts = ( 
  'morning'   => { 'begin' => $dawn,             'end' => $noon},
  'afternoon' => { 'begin' => $noon,             'end' => tmath($dusk, -1) },
  'evening'   => { 'begin' => tmath($dusk, -1) , 'end' => tmath($dusk,  1) },
  'night'     => { 'begin' => tmath($dusk,  1) , 'end' => $dawn}
);