Running Odoo 10 CE on Centos7 with python2.7.  When viewing the Sales Analysis pivot table in the Sales app, selecting Date Order > Week on either axis is resulting in a traceback with the following error:

TypeError: unsupported operand type(s) for -: 'datetime.datetime' and 'datetime.date'

All other Date Order periods seem to work fine.  I came across this post with a similar error: https://www.odoo.com/forum/help-1/question/odoo-v10-enterprise-unsupported-operand-type-s-for-datetime-datetime-on-fresh-install-of-blogs-module-new-blog-post-118028

The post there indicates updating the babel package fixed the issue, but there's no indication of what the required version was.  I'm running the most up-to-date package available in-distro (v0.9.6) for python2.7, but the problem still occurs.  The same error results when selecting Date Order > Week on the Purchase Analysis report as well.

Has anyone else seen this issue?  Any advice for troubleshooting?  Thanks in advance.

EDIT:

For reference here is the full traceback from the log:

533 4935 ERROR odoo-db odoo.http: Exception during JSON request handling.
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/odoo/http.py", line 642, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "/usr/lib/python2.7/site-packages/odoo/http.py", line 684, in dispatch
    result = self._call_function(**self.params)
  File "/usr/lib/python2.7/site-packages/odoo/http.py", line 334, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "/usr/lib/python2.7/site-packages/odoo/service/model.py", line 101, in wrapper
    return f(dbname, *args, **kwargs)
  File "/usr/lib/python2.7/site-packages/odoo/http.py", line 327, in checked_call
    result = self.endpoint(*a, **kw)
  File "/usr/lib/python2.7/site-packages/odoo/http.py", line 942, in __call__
    return self.method(*args, **kw)
  File "/usr/lib/python2.7/site-packages/odoo/http.py", line 507, in response_wrap
    response = f(*args, **kw)
  File "/usr/lib/python2.7/site-packages/odoo/addons/web/controllers/main.py", line 895, in call_kw
    return self._call_kw(model, method, args, kwargs)
  File "/usr/lib/python2.7/site-packages/odoo/addons/web/controllers/main.py", line 887, in _call_kw
    return call_kw(request.env[model], method, args, kwargs)
  File "/usr/lib/python2.7/site-packages/odoo/api.py", line 687, in call_kw
    return call_kw_model(method, model, args, kwargs)
  File "/usr/lib/python2.7/site-packages/odoo/api.py", line 672, in call_kw_model
    result = method(recs, *args, **kwargs)
  File "/usr/lib/python2.7/site-packages/odoo/models.py", line 1939, in read_group
    result = self._read_group_raw(domain, fields, groupby, offset=offset, limit=limit, orderby=orderby, lazy=lazy)
  File "/usr/lib/python2.7/site-packages/odoo/models.py", line 2044, in _read_group_raw
    result = [self._read_group_format_result(d, annotated_groupbys, groupby, domain) for d in data]
  File "/usr/lib/python2.7/site-packages/odoo/models.py", line 1884, in _read_group_format_result
    tzinfo=tzinfo, locale=locale
  File "/usr/lib/python2.7/site-packages/babel/dates.py", line 508, in format_datetime
    return parse_pattern(format).apply(datetime, locale)
  File "/usr/lib/python2.7/site-packages/babel/dates.py", line 702, in apply
    return self % DateTimeFormat(datetime, locale)
  File "/usr/lib/python2.7/site-packages/babel/dates.py", line 699, in __mod__
    return self.format % other
  File "/usr/lib/python2.7/site-packages/babel/dates.py", line 726, in __getitem__
    return self.format_week(char, num)
  File "/usr/lib/python2.7/site-packages/babel/dates.py", line 797, in format_week
    day_of_year = self.get_day_of_year()
  File "/usr/lib/python2.7/site-packages/babel/dates.py", line 863, in get_day_of_year
    return (date - date_(date.year, 1, 1)).days + 1
TypeError: unsupported operand type(s) for -: 'datetime.datetime' and 'datetime.date'