[…] when the start_time = ‘2015-09-01T07:00:00Z’ and end_time = ‘2016-02-20T07:00:00Z’, it worked fine […]
(in America/Los_Angeles timezone) but I did some testing just now, and it seems that each date has to be in its own DST - this way it doesn’t throw an error. So the way it would have worked in the case above would have been like this:
start_time = '2015-09-01T07:00:00Z'
end_time = '2016-02-20T08:00:00Z'
since the DST changed on 2015-11-01 for America/Los_Angeles ( http://www.timeanddate.com/time/change/usa/los-angeles?year=2015 ).
Can you confirm that the interval you first posted throws an error in fact?