Incorrect duration sets for recurring events when use custom New Form for SharePoint Calendars

I made a custom NewForm.aspx for the calendar list to enter datas then when I add a new recurring event to repeat the event every day until next 2 months and save the event, It just repeats the event for just one month and not any more and EndEvent column has the value of StartEvent ! but when I do the same things with the SharePoint original NewForm , It works properly ! It's going to make me crazy :| what's the differece and why it happens !