When you set, for example, DisplayDateStart to 1/1/2011, DisplayDateEnd to 1/1/2012 and DateSelectionMode to Year, the RadDateTimePicker displays 2010 too. You can interact with the years within the range but not with the additional one. The way to avoid this activity is to set DisplayDateStart to 2/1/2011 (according to the given example) but the day corresponding to the 1/1/2011 will not be included.

This is an issue with both a binding and a hard-set value

RadDateTimePicker cannot parse datetime string when Windows date format is set to "Chinese (Traditional, Taiwan)".

RadDateTimePicker ControlTemplate: PopupPlacementTarget in RadDropDownButton is not respected when FlowDirection of RadDateTimePicker is RTL. PopupWrapper issue.

For example if you have 12:00 selected and input 15:03 in the WatermarkTextbox- 12:00 item of the Clock is still selected

If the InputMode of the DateTimePicker is set to TimePicker the DateTimeWatermarkContent states €œEnter Date€ and it should state €œEnter Time€.

When StartTime = EndTime all hours are visable (12 am - 11pm)
Workaround:
Select EndTime in one hour interval from StartTime (10:00 - >10:01). In this situation only 10:00 will be visible

When FlowDirection is RTL, navigating in Calendar and Clock is inverted- pressing left arrow moves the selection to the right and vice versa.

When set DateSelectionMode="Month" and SelectionMode="CenturyView", the calendar in the dropdown starts from YearView instead of CenturyView

When the control is declared in XAML, and we place the caret somewhere on the control the VS designer is open, and the dropdown is open.

The milliseconds are not correctly parsed when setting an (f) custom format to the ShortTimePattern property.

A workaround for this would be to implement custom parsing:

private void TimePicker_ParseDateTimeValue(object sender, Telerik.Windows.Controls.ParseDateTimeEventArgs args)
{
    string input = args.TextToParse;

    DateTime res;
    bool isValueParsedSuccessfully = DateTime.TryParse(input, out res);

    if (isValueParsedSuccessfully)
    {
        args.Result = res;
    }
    else
    {
        args.IsParsingSuccessful = false;
    }
}

Available in LIB version 2016.3.1017, it will be also available in the 2016 R3 SP1 release.