A simple test:
Find a copy of Microsoft Excel
Format the fist column as a date
Type 18/12/1901 in the first cell. Excel will recognise that as 18 Dec 1901
Type 18/12/1564 in the next cell down. Excel will think this is a string and leave it as it is
Luckily, Open Office realises that history goes back further than 1900. The Open Malaysia blog goes into the details of this, and I don’t claim to understand the whole story but the upshot of all of it is that this is an application level restriction that affects the native Office formats rather than the xml export formats, and it is being proposed as an ISO standard to come into force in September.
I can’t put it better than the Open Malaysia blog:
“…please avoid the native file formats of [Microsoft Office] if you are a Islamic historian, Renaissance archivist, Medieval coin collector, or someone who just has to work with dates prior to the 20th Century. ”
Best stick with Open Office then!