C# – Add Generic list in a MyClass but how

How can i add list in a generic class?
Firstly My generic Class is that:

[Serializable]
    public class ScheduleSelectedItems
    {
        private string Frequency;
        List FrequencyDays = new List();
        private string Time;
        private string StartTime;
        private string EndTime;
        private string StartDate;
        private string EndDate;
        private string Name;


        public ScheduleSelectedItems(string frequency,List frequencydays,
                                     string time, string starttime,
                                     string endtime, string startdate, 
                                     string enddate, string name)
        {
            Frequency = frequency;
            FrequencyDays = frequencydays;
            Time = time;
            StartTime = starttime;
            EndTime = endtime;
            StartDate = startdate;
            EndDate = enddate;
            Name = name;
        }
    }

    [Serializable]
    public class ScheduleSelectedItemsList
    {
        public List Items;

        public ScheduleSelectedItemsList()
        {
            Items = new List();
        }
    }

and i want to add ScheduleSelectedItems into ScheduleSelectedItemsList in form1.cs
Form1.cs codes is here :

private void timer1_Tick(object sender, EventArgs e)
        {
            string saat = DateTime.Now.ToShortTimeString();
            string bugun = DateTime.Today.ToShortDateString();
            ScheduleMng smgr = new ScheduleMng();
            ScheduleItemsList schlist = smgr.LoadXml();
            List list = new List();

            for (int i = 0; i = Convert.ToDateTime(schlist.Items[i].StartDate.ToString())
                     && Convert.ToDateTime(bugun) 

slist.Items.Add(list); —-> i don't use theese codes . These error "included some invalid argument" how can you help me? 🙂