If we use the following code: // Navigate to : 'http://demos.kendoui.com/web/calendar/index.html' ActiveBrowser.NavigateTo("http://demos.kendoui.com/web/calendar/index.html"); //Get the Calendar object KendoCalendar calendar = ActiveBrowser.Find.ById<KendoCalendar>("calendar"); //Select date calendar.selectDay("2013, 09, 18"); It will select 18th October 2013, not 18th September 2013. This is counterintuitive since in C#, DateTime months are not Zero-based as they are in JavaScript Date Object.