We're querying the api/web/lists/GetByTitle('xxx')/items endpoint in SPO and trying to apply $filter to a date field. For some users the date string needs to be in the 2016-09-05T05:00:00.000Z format and others the 09-05-2016 format. Why?
Example:
api/web/lists/GetByTitle('xxx')/items?$select=Id,cdpv,ResourceId,Hours,ProjectId&$filter=(ResourceId eq ‘9’) and (cdpv eq ‘2016-09-05T05:00:00.000Z’)&$top=5000