[Solved] ASP.Net DateTime ParseExact Error: String was not recognized as a valid DateTime

I am trying to inserting time (HH:mm:ss) to database from GridView, it is giving error

String was not recognized as a valid DateTime.

protected void update_Click(object sender, EventArgs e)
{
    foreach (GridViewRow row in this.GVTime.Rows)
    {
        var AttIDS = row.FindControl("R_ID") as Label;
        var date2 = (row.FindControl("txtINTime") as TextBox).Text;
        var date3 = (row.FindControl("txtOuttime") as TextBox).Text;
        DateTime INTime;
        if (!string.IsNullOrEmpty(date2))
        {
            INTime = DateTime.ParseExact(date2, " h:mm:ss tt", CultureInfo.InvariantCulture);
        }
        else
        {
            INTime = System.DateTime.Now;
        }

        DateTime Outtime;
        if (!string.IsNullOrEmpty(date3))
        {
            Outtime = DateTime.ParseExact(date3, "h:mm:ss tt", CultureInfo.InvariantCulture);
        }
        else
        {
            Outtime = System.DateTime.Today;
        }
        SqlCommand cmd = new SqlCommand("SP_Insert_Emp_Time", con);
        cmd.CommandType = CommandType.StoredProcedure;

        cmd.Parameters.AddWithValue("@R_ID", AttIDS.Text);
        cmd.Parameters.AddWithValue("@TimeIN", date2);
        cmd.Parameters.AddWithValue("@TimeOut", date3);
        if ((date2 == ""))
        {
            cmd.Parameters["@TimeIN"].Value = DBNull.Value;
        }
        else
        {
            cmd.Parameters["@TimeIN"].Value = DateTime.Parse(date2);
        }

        if ((date3 == ""))
        {
            cmd.Parameters["@TimeOut"].Value = DBNull.Value;
        }
        else
        {
            cmd.Parameters["@TimeOut"].Value = DateTime.Parse(date3);
        }
        con.Open();
        cmd.ExecuteNonQuery();
        con.Close();
    }
}

error on below line

Line 60:             foreach (GridViewRow row in this.GVTime.Rows)