Problem with "Within next" collection criteria in Plone 5.0.4

[cekk]

Hi,
i don't know if this is the right place to open this issue (maybe on p.a.collection?) but i have an error with Plone 5.0.4 (vanilla).
If i create a new collection and select a date field (for example event's start date) and then select "within next" criteria, there is a js error (server error on the backend call) and in the log i have the following traceback:

Traceback (innermost last):
Module ZPublisher.Publish, line 138, in publish
Module ZPublisher.mapply, line 77, in mapply
Module ZPublisher.Publish, line 48, in call_object
Module plone.app.querystring.querybuilder, line 97, in html_results
Module plone.app.querystring.querybuilder, line 88, in call
Module plone.app.querystring.querybuilder, line 128, in _makequery
Module plone.app.querystring.indexmodifiers.query_index_modifiers, line 70, in call
Module dateutil.parser, line 1008, in parse
Module dateutil.parser, line 392, in parse
Module dateutil.parser, line 492, in _parse
Module dateutil.parser, line 174, in split
Module dateutil.parser, line 171, in next
Module dateutil.parser, line 164, in next
Module dateutil.parser, line 82, in get_token
Module DateTime.DateTime, line 1118, in getattr
AttributeError: read

I've investigated a bit, but i don't know what could be the problem. I only noticed that DateTime and python_dateutil are updated from Plone 5.0.2 an 5.0.4. I tried to downgrade them but it doesn't fix the error.
Some ideas?