Firewall Firmware Schedule Date - Local Time vs UTC

You have the selection of the timezone, so the firewall is aware of its timezone. 

If you select the the time to update, it is the "local time" in that specific timezone.

Sounds like it did exactly what it should - What was the confusing part about this one? 

Sorry I thought I was pretty clear about this. If an API wants the time specified in "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'" format, then that's UTC time. If the API instead interprets this in local time then that behaviour should be documented.

Here's some info on Zulu/UTC time and what that means when a Z is appended to a time format ISO 8601 - Wikipedia

So - i was looking into this, but i cannot spot any kind of Zulu time.

Yes the UI only talks about local time. Are you understanding that it's the API i'm referring to where the documentation (or behaviour) is incorrect? I'm posting in the API forum, but i never actually said "API" in my original post, which was maybe an oversight on my part.

the API doco relevent to this issue is here Firewall API | Sophos Central APIs

Ah, you are right, i was referring to the UI. 

We are going to investigate and might change this later.