programmatically add 30 rows whit date

in asp.net web application I have gridview whit columns date(datetime) Jony(nvarchar(10)) Ana(nvarchar(10))  Katya(nvarchar(10)) Steve(nvarchar(10)). Its binding from sqldatasource (tblUserreport). I have button in gridwiev footer and on onbuttonclick function I want to call  sored procedure that add 30 rows in table whit populate date cells whit increment date +1 butt other cells(ana jony steve) to be null.