I am assuming you are referring to this page?
Trim the date to hours, rounding off all minutes down to zero. trimToHours uses the server's calendar and trimToHoursUTC uses the UTC calendar.
I see the text above on that page, and you are correct. The text isn't correctly written, the normal trim function uses the TimeZone that is available on the server and not UTC. When a user triggers a microflow it will also pass/use a TimeZone, and that time zone will be used for the trim functions.
The regular trim action will therefore always use the users TimeZone, a scheduled event will use the TimeZone specified in the project settings.
Hi Martin, Thanks for the feedback. I've updated the documentation accordingly.