Time Zone glitch in iOS 15.6.1 regarding Atlantic time

Thank you for the suggestion, but it didn't help. The problem persists after executing both steps. The San Juan PR year-round Atlantic Standard Time (AST) setting is still being changed by iOS to Atlantic Daylight Time (ADT).

I'm not sure I understand the instruction - what would I be updating, relative to this issue, by plugging my iPhone into my computer?

Another point of reference that may or may not be relevant is that when I create a calendar event in my iPhone and I use any other time zone (e.g. I've used San Diego, I've used San Juan Argentina, and I've used Denver), that calendar event's times sync properly to Outlook for my local and the event's local times. It's only when I use the San Juan Puerto Rico time zone (which is always AST) that iOS changes it to ADT, when ADT is in effect wherever ADT is used (which is not Puerto Rico). Not sure whether this matters for this discussion and troubleshooting.

Thanks again for your suggestions!

PC. Windows 10 Pro operating system. New in March 2022.

When you say, "When you update from your computer...", when I update what from the act of plugging my phone into my computer? You say "it sends cellular updates as well", but "as well" as what else?

What isn't updating in my iPhone when I do the regular iOS updates over the air? I don't understand what the act of plugging my phone into my computer would do above and beyond the over the air updates, other than the cellular updates you mention, that would have any bearing on this Time Zone issue.

And again, thanks for your persistence!

I've done the experiment both ways, and both ways iOS changes the calendar time zone to ADT for San Juan, PR.

So an event entered in my iPhone calendar and starting at 9am local time (e.g. AST) in San Juan shows up as 8am in my Outlook calendar when they sync, because iOS thinks it's starting at 9am ADT rather than 9am AST.

That seems to relate to updating iOS on my device, and using a PC and iTunes to do so. But I don't need to update my device's iOS that way, because it's: 1) set up for WiFi syncing, 2) Automatic Updates is turned On, and 3) iOS says it's up to date (v. 15.6.1).

Step #4 at the link, "Click Check for Update", would say that no updates are available, because I'm already on the latest iOS version, because that's what my device says (15.6.1 being the most current version).