$month="January";

%months=('January'  =>01,
	 'February' =>02,
	 'March'    =>03,
	 'April'    =>04,
	 'May'      =>05,
	 'June'     =>06,
	 'July'     =>07,
	 'August'   =>08,
	 'September'=>09,
	 'October'  =>10,
	 'November' =>11,
	 'December' =>12
	);
#  if($month ?in? %months)
#  { $month=%months{$month}; }

print "$month\n";  #output-> "01"