[Solved] SQL Server Error: Type date is not a defined system type

1 USER LOGIN. 50 FRND SHOW IN LIST.

SOME FRND BDAY CURRENT MONTH, 20 FRND BDAY DEC MONTH, 5 FRND BDAY APRIL, 10 FRND BDAY OCT MONTH.

I WANT TO SHOW THE FRIEND LIST WITH CURRENT MONTH BDAY.

BELOW QRY RUN TWO TIME . 1ST TIME .NET . NO DATA SHOW. 2ND TIME SAME QRY RUN IN SQL ERROR MSG SHOW

Type date is not a defined system type

string qry = "select a.*,b.*,c.* from tblfrequst a join tbluserinfo b on a.to_id=b.id"
                + " join tbluserprofilepicture c on c.id=b.id"
                + " where a.from_id=" + ID + "and a.request_status='AC' AND DATEPART(MONTH,CONVERT(date, b.D_O_B, 105)) = DATEPART(MONTH,GETDATE())"
                + " UNION "
                + " select a.*,b.*,c.* from tblfrequst a join tbluserinfo b on a.from_id=b.id"
                + " join tbluserprofilepicture c on c.id=b.id"
                + " where a.to_id=" + ID + "and a.request_status='AC' AND DATEPART(MONTH,CONVERT(date, b.D_O_B, 105)) = DATEPART(MONTH,GETDATE())";