Comment 27 for bug 391572

It's worse that that, you CAN display dates as ISO. but when you try editing
them, and you are confronted by some unknown format, if you experiment, you can
find out what it is (possibly mm/dd/yy) the default format seems not to be
affected by the default locale setting of your machine so dates are largely
unusable in open office calc. Sadly now Open office is so popular, that other
open source spreadsheets appear to have been abandoned. My latest distro
includes Open office calc as the ONLY spreadsheet, so if you don't use mm/dd/yy
date format then you're scuppered.