How can I correct Date Indexes in the portal catalog?

I have a container content type that has the field 'end_of_week', which is by default set to the end of the current week.

The end of week field is set one of two ways:
-The user manually enters it
-The date is programatically set

The end_of_week field is defined as:

end_of_week = schema.Datetime(title='End of Week',
                                                      description='Enter date a week ends (on Sat)'

Unfortunately, I discovered recently that the date programmatically set has tzinfo (set to UTC), whereas the value entered manually doesn't have tzinfo.

When I create the content type programatically, I use:

end_of_week = getWeekRange(myevent.start)['end']

#The 'myevent' object passed, which is to be stored in the container, uses the IEventBasic behavior.
ts_ref = createContentItem(timesheetmanager,
                                   end_of_week = getWeekRange(entry.start)['end'],

In a utils .py file, I have the function that I use to get the end of the week:

def getWeekRange(date_of_entry,offset=1, tz_to_localize=None):
    """Returna dict cotaining the starting and ending dates of a week"""
    start = date_of_entry - timedelta(days = (date_of_entry.weekday() + offset) % 7)
    end = start + timedelta(days=6)
    if tz_to_localize is None:
        return {'start':start.replace(hour=0,minute=0),
        return {'start':tz_to_localize.localize(datetime(start.year,start.month,,0,0)),

When I view the portal_catalog in the ZMI, it does not break.

However, when I add the container type manually and then go into ZMI to see it, it breaks.
This is the error I see when I try to view the values for the 'end_of_week' index.

2017-12-01 12:36:35 ERROR Zope.SiteErrorLog 1512149795.840.529882828129 http://localhost:8080/Plone/portal_catalog/Indexes/end_of_week/manage_browse
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 Shared.DC.Scripts.Bindings, line 322, in __call__
  Module Shared.DC.Scripts.Bindings, line 359, in _bindAndExec
  Module App.special_dtml, line 185, in _exec
  Module DocumentTemplate.DT_Let, line 77, in render
  Module DocumentTemplate.DT_In, line 606, in renderwb
  Module DocumentTemplate.DT_Util, line 210, in eval
   - __traceback_info__: DateTime
  Module <string>, line 1, in <module>
  Module DateTime.DateTime, line 440, in __init__
  Module DateTime.DateTime, line 812, in _parse_args
DateError: Invalid date: (2018, 0, 2, 23, 59, 0, 'UTC')

So right now I'm trying to make an upgrade step that would correct the indexes.

from pytz import utc
def _upgrade_step(context):
    catalog = api.portal.get_tool(name='portal_catalog')
    brains = catalog.searchResults({'portal_type':'my.product.containertype'})
    for i in brains:
        obj = i.getObject()
        og_date = i['end_of_week']
        if obj.end_of_week.tzinfo is None:
            obj.end_of_week=utc.localize(datetime(og_date.year, og_date.month,, 23, 59))

Unfortunately, this does not work as I still end up with the same error.

I changed the upgrade step to verify that all the end_of_week values had a timezone assigned.

for i in brains:
    print i['end_of_week'], ' ', i['end_of_week'].tzinfo

In the print statements, the results all appear correct as they should, but when I go into the catalog, it breaks.

I noticed in the error message, the time tuple displays the incorrect value for the year parameter, when it should've been 2017 instead of 2018.

What can I do to fix the indexes? An upgrade step would be ideal at the moment.

I tried making a new index to see if I was doing schema.Datetime correct.

<index name="experiment_date" meta_type="DateIndex">
	<indexed_attr value="experiment_date"/>
<column value="experiment_date"/> 	

In a new content type:

class IDateTest(model.Schema):
    experiment_date = schema.Datetime(title=_(u"Experiment Date"),
                                      required = True)

class DateTest(container):

I created a 'DateTest' and went to portal_catalog and browsed the index, and experiment_date is working.
In this case I didn't have a default for experiment_date.

I thought maybe that could've been causing a problem. So I removed setting the default 'end_of_week' and removed all objects that used the 'end_of_week' index so I can empty the indexes. Then I tried manually adding the container that uses 'end_of_week' manually and checked the catalog again. Unfortunately, this did not work as the same error appeared.
I did try running Clear and Rebuild Catalog, but that did not work as I still ended up with the same error. I'm thinking the 'end_of_week' index I have is permanently bugged.

I found something interesting. It appears to possibly be generating a random number.

I tried an experiment with the DateIndex in which I had a property function return pass. The index I used was filled with some random number.