Unfortunately, the Calendar (and DatePicker) do not support selection of months only. The SelecionChanged event is not fired because no actual selection has occurred, the user has only navigated to another month/year.
The DisplayMode property only reflects in which mode the calendar is at the moment, but does not limit the user navigation.
We have not yet considered adding this selection mode for the calendar.
As an alternative, you can have a look at the MaskedTextBox which supports year/month-only entry:
Hopefully this will work in your scenario,
the Telerik team
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