windows service to run once in a week

how to make windows service to run on every monday at 12 : 00 AM

please guide me .

i have tried following one..

 protected void InitializeTimer()
    {            
        if (timer1 == null)
        {
            timer1 = new Timer();
            timer1.AutoReset = true;
            var todayInWeek = DateTime.Now.Date.DayOfWeek;
            DateTime _scheduleTime = DateTime.Parse(System.Configuration.ConfigurationManager.AppSettings["ScheduledTime"]);
            if (todayInWeek == DayOfWeek.Monday)
            {
                timer1.Elapsed += new ElapsedEventHandler(schedular());
            }

        }           
    }

    private void schedular(object sender, ElapsedEventArgs e)
    {
        try
        {

        }
        catch (Exception ex)
        {

        }
    }