Calendar field for dates always displays DD/MM/YYYY, regardless of plugin settings

I have DD.MM.YYYY and I cannot change that format. Though it's not supported by this plugin, right? Anyway the combobox does not offer such choice.

Replying to falkb:

I have DD.MM.YYYY and I cannot change that format.

sorry, I mean %Y-%m-%d

related to #10382

(In [13092]) v1.2.0, minor release

changes:

• improved the behavior of the javascript date picker (now beta), refs #10626:
  • now using jQuery date picker
  • now allowing more date formats
• date format, refs #10382:
  • now the date format YYYY-MM-DD is allowed

The calendar field will now work with other date formats as well. Please do not hesitate to report any error you are observing.

if use_ajax_for_fetching_reports is enabled, Error: report (of ProjectPlan) could not be rendered. is displayed; if it's disabled, this traceback appears:

[2013-05-14 09:08:27,473 p3492:t2984] formatter.py:768 ERROR: Macro ProjectPlan(combine_filters=AND,filterlike_milestone=123 - Foo - X5,segments=20/02/2012;21/02/2012;22/02/2012;23/02/2012;24/02/2012,renderer=tableticketperuserday,owners=falkb;test,cssclass=blacktable, useimages=Y, summary=chart,showaggregatedstate=T,statistics=elapsed_time/estimated_time) failed: 
Traceback (most recent call last):
  File "build\bdist.win32\egg\trac\wiki\formatter.py", line 765, in _macro_formatter
    return macro.ensure_inline(macro.process(args))
  File "build\bdist.win32\egg\trac\wiki\formatter.py", line 356, in process
    text = self.processor(text)
  File "build\bdist.win32\egg\trac\wiki\formatter.py", line 343, in _macro_processor
    text)
  File "build\bdist.win32\egg\projectplan\projectplan.py", line 385, in expand_macro
    return ProjectPlanGenerator.get_html( macroenv, formatter.req, content )
  File "build\bdist.win32\egg\projectplan\projectplan.py", line 472, in get_html
    renderer.render( ts ),
  File "build\bdist.win32\egg\projectplan\pprender.py", line 1173, in render
    return self.concreteRenderer.render( ticketset )
  File "build\bdist.win32\egg\projectplan\renderer\ppticketsperuserday.py", line 262, in render
    if  self.showAggregatedTicketState()  and  calendar[segment]['date'] < currentDate:
TypeError: can't compare datetime.date to NoneType

Also, a newly created ticket contains the strings "YYYY-MM-DD" in custom ticket fields 'userstart' and 'userfinish' now!