I had a coworker ask me what time zone the scheduler ran in; so I (@ Server location, US Central Standard) poked at it a little bit with another coworker (US Eastern). I had her schedule a job a couple minutes into the future to see if it ran on her time or mine. We learned a handful of helpful things:
I've posted some pictures below that show her results screen and the schedule listing from the Admin side of the Gallery, respectively, to show the discrepancy.
The test was performed on Server version 11.7 on 2018-06-11. This post is for informational purposes only. For my suggested fix, see this Idea