请协助安排任务

我试图创建一个计划任务(使用计划任务包装器)每3小时触发一次。我每天都要安装这个任务，但即使看了文档，也不能每隔几个小时运行一次。也不太确定LogonType。谁能告诉我我哪里做错了?

        private void button1_Click(object sender, EventArgs e)
    {
        using (TaskService ts = new TaskService())
        {
            var androback = ts.GetTask("Andro_Inc_Backup");
            bool taskExists = androback != null;
            if (taskExists)
            {
                MessageBox.Show("Andromeda incremental backup task already installed");
            }
            else
            {
                TaskDefinition td = ts.NewTask();
                td.RegistrationInfo.Description = "Incremental Backup";
                td.Principal.LogonType = TaskLogonType.ServiceAccount;
                td.Triggers.Add(new DailyTrigger { DaysInterval = 1 });
                td.Actions.Add(new ExecAction("C:''Rameses''Program''Inc_Cloud_Backup.exe", null));
                const string taskname = "Inc_Backup";
                ts.RootFolder.RegisterTaskDefinition(taskname, td);
                MessageBox.Show("Incremental Backup Task Installed");
            }
        }
    }

DateTime datetime = DateTime.Today;
DateTime startDateTime = new DateTime(datetime.Year, datetime.Month, datetime.Day, 0, 0, 0);
DailyTrigger dailyTrigger = new DailyTrigger { StartBoundary = startDateTime, Enabled = true, DaysInterval = 1 };
dailyTrigger.Repetition.Interval = TimeSpan.FromHours(23);
dailyTrigger.Repetition.Interval = TimeSpan.FromHours(3);
td.Triggers.Add(dailyTrigger);