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;
    }
}