Thank you for the request.
RadDateTimePicker does not support such functionality. I would like to suggest customizing RadSpinEditor for your purposes.
You can set RadSpinEditor's Minimum to 0 and Maximum to 24 and hide the upper arrow button with this lines of code:
radSpinEditor1.Maximum = 24
radSpinEditor1.Minimum = 0
radSpinEditor1.SpinElement.UpButton.Visibility = Telerik.WinControls.ElementVisibility.Collapsed
You will notice that there is empty space above the down arrow button. This behavior cannot be worked around and the down arrow button cannot be extended to fill the whole RadSpinEditor height.
Do not hesitate to contact us if you have other questions.
the Telerik team
Q3’10 SP1 of RadControls for WinForms is available for download
; also available is the Q1'11 Roadmap
for Telerik Windows Forms controls.