string firma = "";
    private void radButton1_Click(object sender, EventArgs e)
    {
        try
        {
            for (int i = 0; i < radGridView4.Rows.Count; i++)
            {
                DateTime executionTime = Convert.ToDateTime(radGridView4.Rows[i].Cells[10].Value.ToString());
                ScheduleAction(action, executionTime);
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex);
        }
    }

    public async void ScheduleAction(Action action, DateTime ExecutionTime)
    {
        try
        {
            if (DateTime.Now < ExecutionTime)//ExecutionTime only create an alarm for rows that are later than now
            {
                await Task.Delay((int)ExecutionTime.Subtract(DateTime.Now).TotalMilliseconds);

                action();
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex);
        }
    }

    public void action()
    {
        RadDesktopAlert Alert;
        for (int i = 0; i < radGridView4.Rows.Count; i++)
        {
            DateTime executionTime = Convert.ToDateTime(radGridView4.Rows[i].Cells[10].Value.ToString());

            if (DateTime.Now.Date == executionTime.Date && DateTime.Now.Hour == executionTime.Hour && DateTime.Now.Minute == executionTime.Minute)
            {
                Alert = new RadDesktopAlert();

                firma = radGridView4.Rows[i].Cells[2].Value.ToString();

                Alert.CaptionText = "Telefonmøde";
                Alert.ContentText = firma;
                Alert.Show();

            }
        }
    }