select convert(varchar(10),dateadd(DAY,t2.number,t1.day),120) day from
(select substring(convert(varchar,GETDATE(),120),1,7)+'-01' day) t1,
(select number from MASTER..spt_values WHERE TYPE='P' AND number>=0 and number<=31) t2
where convert(varchar(10),dateadd(DAY,t2.number,t1.day),120) like substring(convert(varchar,GETDATE(),120),1,7)+'%'