Whenever I open my financial reports in libre calc the date fields are all displayed as: 31/12/1899 00:00:00.
Microsoft Office displays all the dates in the file correctly.
I uploaded the file (with the irrelevant info omitted):
link text
EDIT:
Apparently, libre calc resets all the dates to null values when it reads the file.
I took another xls file and made sure the dates were all valid then used MS Office to save it as an xlsx.
Openning the xls file with LO calc resets the date values. To my surprise, openning the xlsx files worked, the dates didn’t reset.
Here’s the xls file for your viewing pleasure (watch how the dates are valid before openning the file).
It’s a bug in calc’s xls support, I should just add it to LO’s bug tracker, Right?