DateTime->season?

[David E . Wheeler]

Hey All,

Someone on the Bricolage list needed a season method, so I whipped up  
this ugly one:

    sub season {
        my $date = shift->strftime('%m-%d');
        return $date lt '03-21' ? 'winter'
             : $date lt '06-21' ? 'spring'
             : $date lt '09-21' ? 'summer'
             : $date lt '12-21' ? 'autumn'
             :                    'winter';
    }

Since seasons can sometimes change on the 22nd instead of the 21st,  
this isn't quite right. Anyone else done something like this but more  
accurate?

Best,

David