Article: https://www.reuters.com/world/us/us-house-vote-bill-make-daylight-saving-time-permanent-2026-07-09/
Looking at the text of the bill itself[^1], there is no date of effectiveness, so it would take effect immediately upon signing. States currently not observing DST (i.e. Hawaii and most of Arizona) can remain on standard time, but everyone else would be advanced an hour year-round. Because no territories currently observe DST, the bill would de facto have no effect there.
Interestingly, there is nothing that specifies whether standard or daylight time is used in Hawaii, Arizona, and the territories if they don't explicitly pass a bill, but I presume common sense would prevail in that nothing changes.
A parallel bill (S.29) was introduced in the Senate.
When the Senate passed the 2021 version of this bill (March 15, 2022) they amended it to be effective November 5, 2023. The bill was held in the house until the end of the session and died.
https://www.congress.gov/bill/117th-congress/senate-bill/623
The language from the bill has already passed the committee (May 21, 2026) as an amendment to another transportation bill.
https://www.congress.gov/bill/119th-congress/house-bill/7389/text
There IS wording in the bill that allows the areas currently following standard time year round to remain on standard time, if they choose to do so.
(b) Standard time for certain States and areas.
The standard time for a State that has exempted itself from the provisions of section 3(a) of the Uniform Time Act of 1966 (15 U.S.C. 260a(a)), as in effect on the day before the date of the enactment of the Sunshine Protection Act of 2025, pursuant to such section, or an area of a State that has exempted such area from such provisions pursuant to such section, shall be, as such State considers appropriate—
(1) the standard time for such State or area, as the case may be, pursuant to subsection (a) of this section; or
(2) the standard time for such State or area, as the case may be, pursuant to subsection (a) of this section as it was in effect on the day before the date of the enactment of the Sunshine Protection Act of 2025.
It is a messy situation since the bill effectively redefines each time zone to be one hour less offset from UTC and ends daylight saving time. So if Arizona decides to opt out of the change they would be on MST (UTC-7) while the rest of the mountain time zone would be on MST (UTC-6). Hawaii would be on HST (UTC-10) while western Alaska would be on HST (UTC-09). Puerto Rico would be AST (UTC-4) while Pituffik Space Base Greenland (formerly Thule Air Force Base) would be on AST (UTC-3).
A version of this bill has been introduced in both the house and senate every session since 2018. The 2021 version is the only one that passed either body. That history leads me to believe that IF it passes both bodies it will get an effective date in November 2027 - the full year notice that is requested by this list.