The 'Usage' tab of maps and apps in AGOL show usage activity based on GMT time reporting.
I'm in California, it is now 9:41 am and when I wanted to see usage details for the past 24 hours I got this:
Mar 29, 2017, 4:41:21 PM GMT to Mar 30, 2017, 4:41:21 PM GMT
My local time zone is GMT -7 which requires to subtract 7 from the time indicated in the graph in order to find the actual time. If there was an activity on 2:00 GMT I know it was at 7am PST.
It would be nice to see local time in the graph.