How do multiple date queries differ between Craft 2 and 3
My Craft 3 version is:

{% set result = craft.entries()
    .section('events')
    .eventDate( ['and', '&lt;' ~ now|atom, '&gt;' ~ now|date_modify('-6 days')|atom ] )
    .results(':notempty:')
    .orderBy('eventDate desc')
    .limit(3)
    .with(['imageGallery'])
    .all()
%}


Note the extra |atom after the date_modify('-6 days')