Phoenix AZ timezone issue
🧭 Problem Summary Arizona remains one of the few U.S. states that does not observe Daylight Saving Time (DST) since 1968. However, it identifies its time zone as Mountain Standard Time (MST) — which does change to MDT when DST applies elsewhere. Because of this, every spring and fall, Arizona’s effective time alignment shifts: In summer, Arizona matches Pacific Daylight Time (PDT). In winter, it matches Mountain Standard Time (MST). This causes systemic issues in digital calendars, automated scheduling, flight bookings, and cross-state business coordination, requiring frequent manual adjustments. 💡 Recommended Solution Create and declare a dedicated time zone: “Phoenix Standard Time.” This would be a fixed, non-DST time zone officially recognized by IANA (the Internet Assigned Numbers Authority) and major platforms (Microsoft, Apple, Google). All digital devices could use it as a unique time zone identifier that never shifts with DST — eliminating confusion and rescheduling errors. It would function similarly to “UTC+7” year-round but would display as “Phoenix Standard Time (PST)” in software systems. Thank you Akbar Jaffer  Akbar Jaffer Office: (415) 335-6950 Mobile: (650) 430-0232 Web: Marketing-QA.com <http://www.marketing-qa.com/> Meeting: Book time W/Akbar <https://calendly.com/ajaffer/> LinkedIn <https://www.linkedin.com/in/akbarjaffer/> | POI Blog <https://pointofintersection.org/>
Who’s going to tell him? David Braverman Inner Drive Technology From: akbar--- via tz <tz@iana.org> Sent: Tuesday 4 November 2025 13:08 To: tz@iana.org Subject: [tz] Phoenix AZ timezone issue 🧭 Problem Summary · Arizona remains one of the few U.S. states that does not observe Daylight Saving Time (DST) since 1968. · However, it identifies its time zone as Mountain Standard Time (MST) — which does change to MDT when DST applies elsewhere. · Because of this, every spring and fall, Arizona’s effective time alignment shifts: o In summer, Arizona matches Pacific Daylight Time (PDT). o In winter, it matches Mountain Standard Time (MST). · This causes systemic issues in digital calendars, automated scheduling, flight bookings, and cross-state business coordination, requiring frequent manual adjustments. 💡 Recommended Solution Create and declare a dedicated time zone: “Phoenix Standard Time.” · This would be a fixed, non-DST time zone officially recognized by IANA (the Internet Assigned Numbers Authority) and major platforms (Microsoft, Apple, Google). · All digital devices could use it as a unique time zone identifier that never shifts with DST — eliminating confusion and rescheduling errors. · It would function similarly to “UTC+7” year-round but would display as “Phoenix Standard Time (PST)” in software systems. Thank you Akbar Jaffer [cid:image001.png@01DC4D8F.C0E557B0] Akbar Jaffer Office: (415) 335-6950 Mobile: (650) 430-0232 Web: Marketing-QA.com<http://www.marketing-qa.com/> Meeting: Book time W/Akbar<https://calendly.com/ajaffer/> LinkedIn<https://www.linkedin.com/in/akbarjaffer/> | POI Blog<https://pointofintersection.org/>
Sorry, that wasn’t fair. Akbar, the time zone you’re looking for is America/Phoenix. It’s in the northamerica data file and it goes back to the advent of standard time in 1883. David Braverman From: David Braverman via tz <tz@iana.org> Sent: Tuesday 4 November 2025 13:35 To: tz@iana.org Subject: [tz] Re: Phoenix AZ timezone issue Who’s going to tell him? David Braverman Inner Drive Technology From: akbar--- via tz <tz@iana.org<mailto:tz@iana.org>> Sent: Tuesday 4 November 2025 13:08 To: tz@iana.org<mailto:tz@iana.org> Subject: [tz] Phoenix AZ timezone issue 🧭 Problem Summary · Arizona remains one of the few U.S. states that does not observe Daylight Saving Time (DST) since 1968. · However, it identifies its time zone as Mountain Standard Time (MST) — which does change to MDT when DST applies elsewhere. · Because of this, every spring and fall, Arizona’s effective time alignment shifts: o In summer, Arizona matches Pacific Daylight Time (PDT). o In winter, it matches Mountain Standard Time (MST). · This causes systemic issues in digital calendars, automated scheduling, flight bookings, and cross-state business coordination, requiring frequent manual adjustments. 💡 Recommended Solution Create and declare a dedicated time zone: “Phoenix Standard Time.” · This would be a fixed, non-DST time zone officially recognized by IANA (the Internet Assigned Numbers Authority) and major platforms (Microsoft, Apple, Google). · All digital devices could use it as a unique time zone identifier that never shifts with DST — eliminating confusion and rescheduling errors. · It would function similarly to “UTC+7” year-round but would display as “Phoenix Standard Time (PST)” in software systems. Thank you Akbar Jaffer [cid:image001.png@01DC4D90.66D0EDB0] Akbar Jaffer Office: (415) 335-6950 Mobile: (650) 430-0232 Web: Marketing-QA.com<http://www.marketing-qa.com/> Meeting: Book time W/Akbar<https://calendly.com/ajaffer/> LinkedIn<https://www.linkedin.com/in/akbarjaffer/> | POI Blog<https://pointofintersection.org/>
IMHO, AI slop doesn't warrant much of a response... but just to be pedantic: - IANA zone America/Phoenix covers the primary concern - Phoenix uses UTC-7, not UTC+7 - IANA doesn't deal with display names - "Phoenix Standard Time (PST)" would be abhorrent for a display name, confused easily with "Pacific Standard Time (PST)" (UTC-8) - In the United States, the English names of time zones are regulated by congress via 49 CFR 71, so one cannot just propose new display names willy-nilly. Did I miss anything? On Tue, Nov 4, 2025 at 11:39 AM David Braverman via tz <tz@iana.org> wrote:
Sorry, that wasn’t fair.
Akbar, the time zone you’re looking for is America/Phoenix. It’s in the northamerica data file and it goes back to the advent of standard time in 1883.
David Braverman
*From:* David Braverman via tz <tz@iana.org> *Sent:* Tuesday 4 November 2025 13:35 *To:* tz@iana.org *Subject:* [tz] Re: Phoenix AZ timezone issue
Who’s going to tell him?
David Braverman
Inner Drive Technology
*From:* akbar--- via tz <tz@iana.org> *Sent:* Tuesday 4 November 2025 13:08 *To:* tz@iana.org *Subject:* [tz] Phoenix AZ timezone issue
🧭 *Problem Summary*
· Arizona remains one of the few U.S. states that *does not observe Daylight Saving Time (DST)* since 1968.
· However, it identifies its time zone as *Mountain Standard Time (MST)* — which *does* change to MDT when DST applies elsewhere.
· Because of this, every spring and fall, Arizona’s effective time alignment shifts:
o In *summer*, Arizona matches *Pacific Daylight Time (PDT)*.
o In *winter*, it matches *Mountain Standard Time (MST)*.
· This causes *systemic issues* in digital calendars, automated scheduling, flight bookings, and cross-state business coordination, requiring frequent manual adjustments. 💡 *Recommended Solution*
*Create and declare a dedicated time zone: “Phoenix Standard Time.”*
· This would be a fixed, non-DST time zone officially recognized by IANA (the Internet Assigned Numbers Authority) and major platforms (Microsoft, Apple, Google).
· All digital devices could use it as a *unique time zone identifier* that never shifts with DST — eliminating confusion and rescheduling errors.
· It would function similarly to “UTC+7” year-round but would display as “Phoenix Standard Time (PST)” in software systems.
Thank you
Akbar Jaffer
Akbar Jaffer
Office: (415) 335-6950
Mobile: (650) 430-0232 Web: Marketing-QA.com <http://www.marketing-qa.com/>
Meeting: Book time W/Akbar <https://calendly.com/ajaffer/>
LinkedIn <https://www.linkedin.com/in/akbarjaffer/> | POI Blog <https://pointofintersection.org/>
Jonathan Leffler <jonathan.leffler@gmail.com> #include <disclaimer.h> Guardian of DBD::Informix - v2018.1031 - http://dbi.perl.org "Blessed are we who can laugh at ourselves, for we shall never cease to be amused." On Tue, Nov 4, 2025 at 12:46 Matt Johnson-Pint via tz <tz@iana.org> wrote:
IMHO, AI slop doesn't warrant much of a response... but just to be pedantic:
- IANA zone America/Phoenix covers the primary concern - Phoenix uses UTC-7, not UTC+7 - IANA doesn't deal with display names - "Phoenix Standard Time (PST)" would be abhorrent for a display name, confused easily with "Pacific Standard Time (PST)" (UTC-8) - In the United States, the English names of time zones are regulated by congress via 49 CFR 71, so one cannot just propose new display names willy-nilly.
Did I miss anything?
Some parts of Arizona do use DST (Navajo nation), and within that, another part (Hopi nation) does not use DST. https://www.timeanddate.com/time/us/arizona-no-dst.html
On Tue, Nov 4, 2025 at 11:39 AM David Braverman via tz <tz@iana.org> wrote:
Sorry, that wasn’t fair.
Akbar, the time zone you’re looking for is America/Phoenix. It’s in the northamerica data file and it goes back to the advent of standard time in 1883.
David Braverman
*From:* David Braverman via tz <tz@iana.org> *Sent:* Tuesday 4 November 2025 13:35 *To:* tz@iana.org *Subject:* [tz] Re: Phoenix AZ timezone issue
Who’s going to tell him?
David Braverman
Inner Drive Technology
*From:* akbar--- via tz <tz@iana.org> *Sent:* Tuesday 4 November 2025 13:08 *To:* tz@iana.org *Subject:* [tz] Phoenix AZ timezone issue
🧭 *Problem Summary*
· Arizona remains one of the few U.S. states that *does not observe Daylight Saving Time (DST)* since 1968.
· However, it identifies its time zone as *Mountain Standard Time (MST)* — which *does* change to MDT when DST applies elsewhere.
· Because of this, every spring and fall, Arizona’s effective time alignment shifts:
o In *summer*, Arizona matches *Pacific Daylight Time (PDT)*.
o In *winter*, it matches *Mountain Standard Time (MST)*.
· This causes *systemic issues* in digital calendars, automated scheduling, flight bookings, and cross-state business coordination, requiring frequent manual adjustments. 💡 *Recommended Solution*
*Create and declare a dedicated time zone: “Phoenix Standard Time.”*
· This would be a fixed, non-DST time zone officially recognized by IANA (the Internet Assigned Numbers Authority) and major platforms (Microsoft, Apple, Google).
· All digital devices could use it as a *unique time zone identifier* that never shifts with DST — eliminating confusion and rescheduling errors.
· It would function similarly to “UTC+7” year-round but would display as “Phoenix Standard Time (PST)” in software systems.
Thank you
Akbar Jaffer
Akbar Jaffer
Office: (415) 335-6950
Mobile: (650) 430-0232 Web: Marketing-QA.com <http://www.marketing-qa.com/>
Meeting: Book time W/Akbar <https://calendly.com/ajaffer/>
LinkedIn <https://www.linkedin.com/in/akbarjaffer/> | POI Blog <https://pointofintersection.org/>
Matt Johnson-Pint via tz said:
- In the United States, the English names of time zones are regulated by congress via 49 CFR 71, so one cannot just propose new display names willy-nilly.
So isn't Phoenix just in Mountain Standard Time (MST) all year round? -- Clive D.W. Feather | If you lie to the compiler, Email: clive@davros.org | it will get its revenge. Web: http://www.davros.org | - Henry Spencer Mobile: +44 7973 377646
Yes On Wed, Nov 5, 2025, 5:11 AM Clive D.W. Feather <clive@davros.org> wrote:
Matt Johnson-Pint via tz said:
- In the United States, the English names of time zones are regulated by congress via 49 CFR 71, so one cannot just propose new display names willy-nilly.
So isn't Phoenix just in Mountain Standard Time (MST) all year round?
-- Clive D.W. Feather | If you lie to the compiler, Email: clive@davros.org | it will get its revenge. Web: http://www.davros.org | - Henry Spencer Mobile: +44 7973 377646
Date: Wed, 5 Nov 2025 13:11:35 +0000 From: "Clive D.W. Feather via tz" <tz@iana.org> Message-ID: <aQtNB_m1vIBuVEok@davros.org> | So isn't Phoenix just in Mountain Standard Time (MST) all year round? It is ... but I think that the point of the OP's message was that they think of themselves as being in Mountain Time in winter, and in Pacific Time in summer (which means that when they see adverts for something happening at a particular time in different zones, they look at the Mountain Time version in winter, and the Pacific Time version in Summer). That's what was meant by: | Because of this, every spring and fall, Arizona’s effective time alignment | shifts I suspect that the home was that inventing a new zone just for them would somehow solve this problem, which I doubt it would, as I doubt that Arizona has enough population for anyone to publish what their time would be (in fact, from what I recall of the way most of this happens, the entire Mountain timezone doesn't ... most ads I have seen seem to give at most Pacific, Central, and Eastern, versions of the time things are to happen, and ignore Hawaii, Alaska, and Mountain, and everywhere else not using the same time as one of LA, Chicago, or New York). kre
On 2025-11-05 09:22, Robert Elz via tz wrote:
On Wed, 5 Nov 2025 13:11:35 +0000, Clive D.W. Feather via tz wrote:
| So isn't Phoenix just in Mountain Standard Time (MST) all year round?
It is ... but I think that the point of the OP's message was that they think of themselves as being in Mountain Time in winter, and in Pacific Time in summer (which means that when they see adverts for something happening at a particular time in different zones, they look at the Mountain Time version in winter, and the Pacific Time version in Summer).
That's what was meant by: | Because of this, every spring and fall, Arizona's effective time alignment | shifts
I suspect that the hope was that inventing a new zone just for them would somehow solve this problem, which I doubt it would, as I doubt that Arizona has enough population for anyone to publish what their time would be (in fact, from what I recall of the way most of this happens, the entire Mountain timezone doesn't ... most ads I have seen seem to give at most Pacific, Central, and Eastern, versions of the time things are to happen, and ignore Hawaii, Alaska, and Mountain, and everywhere else not using the same time as one of LA, Chicago, or New York).
Our local (Spokane, WA, US) PBS network shows default (Pacific) and Mountain (alternate) times on their ads, like: 8/9 MT. As far as I have not heard, no Canadian urban-only, digital-only transmitters have a range extending south of the border, or any network cable or satellite distribution into US markets, unlike major American networks available in every timezone in Canada, from multiple timezones. -- Take care. Thanks, Brian Inglis Calgary, Alberta, Canada La perfection est atteinte Perfection is achieved non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add mais lorsqu'il n'y a plus rien à retrancher but when there is no more to cut -- Antoine de Saint-Exupéry
On 11/4/25 12:08, akbar--- via tz wrote:
🧭 *Problem Summary*
*
Arizona remains one of the few U.S. states that *does not observe Daylight Saving Time (DST)* since 1968.
*
However, it identifies its time zone as *Mountain Standard Time (MST)* — which /does/ change to MDT when DST applies elsewhere.
*
Because of this, every spring and fall, Arizona’s effective time alignment shifts:
o
In *summer*, Arizona matches *Pacific Daylight Time (PDT)*.
o
In *winter*, it matches *Mountain Standard Time (MST)*.
*
This causes *systemic issues* in digital calendars, automated scheduling, flight bookings, and cross-state business coordination, requiring frequent manual adjustments.
💡 *Recommended Solution*
*Create and declare a dedicated time zone: “Phoenix Standard Time.”*
*
This would be a fixed, non-DST time zone officially recognized by IANA (the Internet Assigned Numbers Authority) and major platforms (Microsoft, Apple, Google).
*
All digital devices could use it as a *unique time zone identifier* that never shifts with DST — eliminating confusion and rescheduling errors.
*
It would function similarly to “UTC+7” year-round but would display as “Phoenix Standard Time (PST)” in software systems. ...
Problem solved long ago by the IANA timezone America/Phoenix. -- gil
participants (8)
-
akbar＠marketing-qa.com -
Brian Inglis -
Clive D.W. Feather -
David Braverman -
Jonathan Leffler -
Matt Johnson-Pint -
Paul Gilmartin -
Robert Elz