When you set the minimum time to 2017-09-16 there aren't any results returned:
Oh dear. We moved over to a new set of Elastic code on Friday afternoon and, well, we forgot to deploy the API project to production. That means it was running against an old Elastic index that hasn't been updated since Friday.
I just pushed the button to deploy the project and your API request now returns results.
Sorry about that, thanks for letting us know!