On 7/18/2026 7:13 AM, Brooks Harris via tz wrote:
On my opinion of the Sunshine Protection Act, I suppose "dangerous"
might be too strong an expression. But I see a lot of potential
unintended confluences, even beyond the TzDb and CLDR difficulties. I
hope it doesn't pass, but I don't have the power or influence to
change the outcome. If it happens we'll just have to cope with it. Of
course it could soon be reversed, as happened in 1974.
If we can learn one thing from 1974 it would be that any time zone
change needs better planning.
H.R.11324 - Emergency Daylight Saving Time Energy Conservation Act of 1973
https://www.congress.gov/bill/93rd-congress/house-bill/11324/all-actions
Introduced 11/7/1973
Passed House (311-88) 11/15/1973
Passed Senate (68-10) 12/4/1973 with amendment
Conference report agreed to by house and senate on 12/14/1973
Signed in to law 12/15/1973
Trial period began 1/6/1974
January 6th (first Sunday of January) is probably the worst date for a
northern hemisphere "spring forward". The latest sunrise of the year
usually occurs in the first week of January. (The latest sunrise does
not occur on the shortest day of the year.)
Jumping from a 7:19 am sunrise (New York City) to 8:19 am is the most
jarring way to make the change. (8:06am to 9:06am in Indianapolis was
also jarring.)
The country never got a real test of leaving the clocks set to "Daylight
Time" in October and gradually losing that extra hour of morning sun. An
emergency was declared and Congress felt they should act immediately and
not write a law that would begin the test in October 1975 (nearly a year
notice).
Is the objection to the proposed law based on a desire for early winter
sunrises (instead of later winter sunsets) or because programmers do not
want to change code for long held assumptions such as "EST = UTC-05"?
I'd rather stay away from the personal preference discussion. Keep
planning for the eventuality that there could some day be a day where
EST does not equal UTC-05. Hope that it doesn't happen if the coding is
too difficult. Keep asking governments to give maximum notice when
making changes.
I have asked my Senator to delay permanent DST (if enacted) until
November 2027. I realize that is a big ask as those pushing for
permanent DST would rather not have one more winter of standard time.
And if your code would be affected by a negative leap second you may
want to fix that too.
