TSQL - Function that returns the greater of two given dates

/*

       -- Execution

       select dbo.getGreaterDate( '1/31/2012', '8/30/2012' );

       select dbo.getGreaterDate( '1/31/2012', null );

       select dbo.getGreaterDate( null, '8/30/2012' );

       select dbo.getGreaterDate( null, null );

*/

CREATE function [dbo].[getGreaterDate](

       @date1 date

       , @date2 date

)

returns date

as

begin

       return(

              case when isnull(@date1,'1/1/1900') >= isnull(@date2,'1/1/1900') then @date1 else @date2 end

       );

end

;