Neither Arizona time nor UTC vary by season. Arizona time (at least the parts where we have servers) is always UTC-7. It’s your local timezone that changes based on Daylight Saving Time, and you’re in the best position to be aware of your local changes (there are dozens of variations in the US alone). We use Arizona time because it is the time zone where the affected servers are and UTC is the world standard time zone.

It’s also worth noting that the “standard” abbreviations you’re referring to mean entirely different things in other countries; their use would be confusing and imprecise. -jdw

We’re using an automatic transfer switch to allow shifting power dynamically between two building feeds (which are each “supposed to be” uninterruptible / fully backed up) for equipment that happens not to have redundant power supplies. -jdw