I apologize for the misunderstanding Michael.
Changing the editable options at run-time is unsupported in the Telerik Extensions for ASP.NET MVC. You can try achieving similar behavior using the Grid's
edit event handler instead. Once the even it triggered you can check the dates and if the conditions are met - call the
cancelChanges method.
I also would like to remind you that as of June 2013 the product is no longer supported and that
migrating to Kendo UI is highly recommended.
Regards,
Alexander Popov
Telerik
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