New Post: The problem about expire time.

I found the statement as blow(http://referencesource.microsoft.com/#System.Windows.Forms/winforms/Managed/System/WinForms/DateTimePicker.cs,85):

        [Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]
        public static readonly DateTime MaxDateTime = new DateTime(9998, 12, 31);

It seem that the max value of the DateTimePicker is 9998-12-31, so the time older than 9998-12-31 0:00:00 will cause this exception(such as 9998-12-31 1:00:00).

In the source code of "Task Scheduler Managed Wrapper", I find cod as blow in the FullDateTimePicker:

        private void DataToControls()
        {
            DateTime displayTime = currentValue.Kind == DateTimeKind.Utc ? currentValue.ToLocalTime() : currentValue;
            dateTimePickerDate.Value = displayTime.Date;
                       dateTimePickerTime.Value = displayTime;
                       if (!string.IsNullOrEmpty(utcPrompt))
                utcCheckBox.Checked = currentValue.Kind != DateTimeKind.Unspecified;
        }

When the day older than 9998-12-31 0:00:00, "dateTimePickerTime.Value = displayTime;" will throw a exception.

As I know, FullDateTimePicker is wrapper of Date and Time, and "dateTimePickerTime" just to save the time of days. so if change the statement into

dateTimePickerTime.Value = DateTime.Now.Date + displayTime.TimeOfDay;

or

dateTimePickerTime.Value = dateTimePickerTime.MinDate + displayTime.TimeOfDay;

Maybe the problem will be fixed.

Another option, limit the Datetime input in UI, just not allow to input the Datetime older than 9998-12-31 0:00:00.

Hope it be helpful.