Add custom DateField to collection

I've created a DateField index and created a custom indexer that converts my schema.Data (a field) to a zope DateTime. Indexer appears to work when view the index via zmi.

I've added a the following records entry to registry.xml so that I can access my field in collections.

<records interface=""
    <value key="title">Custom Date Field</value>
    <value key="description"></value>
    <value key="enabled">True</value>
    <value key="sortable">True</value>
    <value key="operations">
    <value key="group">Metadata</value>

The date.lessThan and date.largerThan operators provide a date calendar widget, but don't seem to actually query against the date selected, as all content with the indexed field is returned regardless of the value of those widgets. Is there a missing step? the date.lessThanRelativeDate and date.largerThanRelativeDate widgets seem to function as advertised.

Probably off topic etc., but "just in case":

I made a new content type TTW to test Calendar view in Plone 5

I added the 'Basic event behavior' and noticed that full calendar shows these content types as 'all day', even if they have start and end set.

So, maybe you could look into the other 'Event behaviors' and see if the relevant code is there )

UPDATE: In the calendar view, Events ARE NOT shown correctly.
I have a custom content type that shows correctly, but I have not figured out why yet.