I am trying to retrieve statistics about campaigns reach for one day and for month and I found such discrepancy.
When I requested period with params start_time=2021-11-30T23:00:00, end_time=2021-12-01T23:00:00 and get total_audience_reach = 20756

But when I requested period with params start_time=2021-10-31T23:00:00, end_time=2021-11-30T23:00:00, I get total_audience_reach=0

This day was related to December period. When I requested period with params start_time=2021-11-30T23:00:00, end_time=2021-12-31T23:00:0, I get total_audience_reach=57497

Thanks

This campaign started on Dec 1, 12:00 AM. From the window you’ve provided in the second request, total_audience_reach=0 seems like expected behavior.

Similarly, the first request is capturing one day of data (20756) and the last request is the full campaign reach 57497.