Thank you for your example.
We will research if we can restrict this internally without any drawbacks.
Until then, I can suggest parsing the date on the onChange event to ensure that the first portion of the year is still the same:
I hope this is helpful.
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Feedback Portal
and vote to affect the priority of the items