Some reports include date and time data. Times in reports include a time zone, and the time zone in a report can be in either Coordinated Universal Time (UTC) or local time, where "local" is defined at the time zone of the admin who ran the report or who set up the report schedule.
If a report contains multiple date/time fields, all of them are either UTC or local time throughout the report. In no case will one date/time data use UTC and another date/time data use local time within the same report. See the topic about each report to see which time zone type that the report uses.
This is important for you to know because when you are analyzing report data, you may need to understand that the dates or times may not correspond to the time at the location of the event.
An extreme example that illustrates this point. Say you are an event planning organization working on a New Year's Eve event in Los Angeles, which is in the Pacific Time zone. The list of attendees is finalized by the the onsite event coordinator, approved by the event host, and uploaded to the event folder at 8:16pm local time. The next workday, you get a call from the event host asking why some people showed up and weren't allowed in. You run a Folders and Files report which shows that the final list was uploaded at 3:16am on January 1. You know that you need to convert that to the local time of the user who performed the action, Pacific Time, and you can then share that with the event host and resolve the issue.