Phoenix Time Zone
I keep noticing that my time zone changes to Denver, even though I'm in Phoenix. I notice at least 7 years worth of posts of this being a problem. Most of Arizona does not use day light savings, so this messes up your entire calendar.
The only option is to set time zone manually or change each calendar entry individually. Who would think that Microsoft can fix this problem by using a time zone "Arizona Time Zone". Would expect Apple to find a solution.