How to use datetimePicker in C#

Question

Hi,

    How to use Datetime Picker to insert record into sql Db usin C# code..below is my code..but isn't working , it's a Standalone Application

 AppointmentClass ap = new AppointmentClass();

            string dateString = this.dtP.Text;

int rown=   ap.insert(Convert.ToInt16(cboRepair.SelectedValue), tbDesc.Text, chkLinc.Checked, Convert.ToInt16(cboCustomer.SelectedValue),DateTime.Parse(dateString.ToString()));

showing error like below

when converting a string to datetime parse the string to take the date before putting each variable into Datetime

plz help...