Thanks again Sophie.
Since my query will be run after the end of the shipping period in question and a shipment can’t be made on an order not yet placed I can use end_date of midnight of the last day of the reporting period.
Question - It appears from testing that end_date includes orders place on the end_date. How does end_date get interpreted if it is 2017-12-31 (ie short format)? Is it takenen as 2017-12-31T00:00:00+00:00 or 2017-12-31T23:59:59T00?
Also are all ordror db time staps recorded as GMT (ie +00:00)?
And finaly can you provide a link to good documentation on using apiary? I have found very little usefull information…