the date of PhD award in France
The date the PhD is awarded is almost always the date of the defense in France (and it is usually the date of the defense that counts for France-specific deadlines, such as qualification, post-doctoral scholarships or PhD awards). The only exception I am aware of is
if the PhD is not awarded on the day of the defense (very rare, but it can of course happen!).

Note that the diploma is not typically issued on that day (and, indeed, may take months to be issued), but that it is possible to get a certificate the day itself or in the next few days. Graduate schools are aware of typical deadlines and typically help the student obtain this certificate by these deadlines.