try..
SELECT FormattedMembershipid, Surname, Othername, REPLACE(CONVERT(NVARCHAR, Dateofbirth, 106), ' ', '-',) AS Dateofbirth from tblPersonal WHERE month(Dateofbirth)=3 AND Gender = 'Male';
see..
http://www.w3schools.com/sql/func_datepart.asp[
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