>>I then apply the NumberFormat. I can try to not pass NumberFormat for dates, but I'm afraid the result would be the same.
>>
>>Let me re-try without passing NumberFormat at all.
>
>
>As far as I know, XLS option creates lower Excel file version that has problem recognizing two-number year.
>If you correct values like 23-Jul-08 to 23-Jul-2008 in Ecel, then you wil be able to apply numberformat.

But I'm using real dates in my cursor. Why would it be a problem with the year?