I want to check the expiration date that display in my datagridview. I have a code but not work for me.

private void NotificationForForm()
        {

            foreach (DataGridViewRow drow in dataGridView2.Rows)
            {
                DateTime expdate = DateTime.Parse(drow.Cells[12].Value.ToString());

                TimeSpan tmspn = expdate - DateTime.Now.Date;
                if (tmspn.Days < 1)
                {
                    notification("WARNING", "Attention! A vehicle schedule for nmaintenance is detected. nPlease check your car in your garage.");
                }
            }
}

I want to show notification if they have expired date.