Thank you for your interest in RadScheduler.
No, this is not possible currently. I have logged your request and if there is an increased demand for such feature we will implement it.
As far as I understand, you need to be able to visually determine the time span of an appointment. This can still be achieved with the resizing ability of the appointments. You can simple double click a time slot, enter the subject and insert the appointment. Then you can resize or drag the appointment to adjust the start and end time. Let us know what you think.
the Telerik team