Arizona doesn’t follow Daylight Saving Time, which can make its timezone behavior confusing — especially in the summer months.
Here’s the simplest way to understand it:
Arizona stays on Mountain Standard Time (MST / UTC -7) all year.
From March to November, when most of the U.S. is on Daylight Time, Arizona’s clock matches Pacific Time, even though its timezone is still MST.
Arizona never switches to Mountain Daylight Time (MDT).
How U.S. Timezones Shift During DST
| Region | Standard Time (Winter) | UTC Offset | Daylight Time (Summer) | UTC Offset |
|---|---|---|---|---|
| Pacific Time | PST | UTC -8 | PDT | UTC -7 |
| Mountain Time | MST | UTC -7 | MDT | UTC -6 |
| Arizona | MST | UTC -7 | (No change) | UTC -7 |
This is why Arizona appears to “follow” Pacific Time during DST months — but technically, its timezone never changes.
⚠️ Important Exception: Navajo Nation
The Navajo Nation, which spans parts of Arizona, does observe DST and switches to MDT in the summer. This is the only region within Arizona that changes clocks.
📝 Key Takeaways
Arizona = MST (UTC -7) all year
Matches Pacific Time only during DST (March–November)
Timezone label stays MST, even when offset matches PDT
Watch for Navajo Nation if scheduling in that area