Provide properties to set min/max time of the DateTimePicker, e.g always shows from 8AM to 5PM of everyday.
Are you sure it is done? The time range is not restricted.
This is offered through the min (http://docs.telerik.com/kendo-ui/api/javascript/ui/datetimepicker#configuration-min) and max (http://docs.telerik.com/kendo-ui/api/javascript/ui/datetimepicker#configuration-max) properties of the DateTimePicker