Week starting day is set to Monday (as usual in Europe) in the preferences. Quit and restart was done.
Why :
1) the week is still starting on a Sunday in all the little help calendars (those to help choosing a date field);
2) as the week # (for this week starting Mon, Jul31 and ending Sun, Aug06) in the weekly calendar view is 31 (correct), in the today's Sunday 06 daily view the week # is 32 ? (yesterday saterday daily view shows week 31).

This is disturbing for "french only" users.

Tks