Thanks, that was a necessary setting.
However I still have some issues with the report download.
For a keyword created e.g. one month ago I'd expect - if I set dateRangeType='LAST_7_DAYS' - to retrieve 7 entries, one for each day, about a tuple (CampaignId, AdGroupId, Id), while I get at most 2 or 3 entries about that tuple.
For example, today is 2016/11/18, and I get data for the tuple (CampaignId, AdGroupId, Id) = (xxx,yyy,zzz) just for 2016/11/11 and 2016/11/15 (for 2016/11/11 I get 'Impressions' = 0, so this is not the problem).
Why I can't retrieve all the week days data?
Thanks again!