I am writing a javascript that export information into excell.
One of the data is date. when I enter the data as a string format it work just fine.
Its look like:
<Cell ss:StyleID="str"><Data ss:Type="String">2012-7-16</Data></Cell>

and it works, I am able to open it in excel and see it correctly.
However when I cahnge it into:
<Cell ss:StyleID="date"><Data ss:Type="DateTime">2012-7-16</Data></Cell>
Then it doesn't work, the whole file can not be opened.

this is the only different.
What is wrong and how can I fix it?