as seen in
DOXIA-541, the meaning of the date is not defined in Doxia: then it seems it's up to the content writer to choose...
and it was a wrong choice to name the content of date field of the document as dateCreation variable in DOXIA-315 /
DOXIASITETOOLS-20 r771801 in 2009
let's start by showing the weak sematic before choosing what to do: creation date, last modification date, or even add some more features like multiple dates (for example "created : last modified")?