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PyCon US Time
by Ee Durbin May 20, 2025

May 20, 2025

PyCon US is an annual gathering for the community using and developing the open-source Python programming language. PyCon US has been held in-person and on-location from 2003 to present with exception for 2020 and 2021 in response to the global COVID-19 pandemic. After an initial three year stint in Washington, D.C. USA PyCon US has been hosted in cities across North America in two-year "cycles". PyCon US makes extensive use of software across an annoying number of online and offline systems. These include GNU/Linux servers, PostgreSQL databases, all web browsers, a mobile application, Raspberry Pis, iPads, Zebra printers, printed materials, and human brain matter. These systems persist year-over-year while our timezone does not. This timezone is proposed to provide a durable solution for ensuring agreement between these systems. After over a decade dealing with these concerns, establishment of this timezone will benefit me directly, as well as those who proceed me by reducing churn in our codebases, and entirely obliviate the need to think during stressful periods of conference planning. It will also benefit my co-workers and those who follow them by dissolving an unnecessary cognitive burden when editing records in our systems, communicating deadlines and schedules, and working with one another remotely. It will also benefit attendees in reasoning about these matters. PyCon US Time is defined to be the local time of the city currently hosting the conference. PyCon US Time transitions at the time that last attendee (Larry Hastings, most often) departs the Development Sprints. We are actively working to improve the historic times for this departure, but estimate 8pm local time for years which have not yet been fully verified. Transitions =========== 2003-02-13 First Annual PyCon announced - Reference: https://www.python.org/psf/press-release/pr20030213/ - Location: Washington DC, USA, -5:00 2005-03-25 PyCon US Washington concludes - New Location: Dallas, TX, USA, -6:00 - Last Attendee Departure: Unconfirmed 2007-03-01 PyCon US Dallas concludes - New Location: Chicago, IL, USA, -6:00 - Last Attendee Departure: Unconfirmed 2009-04-02 PyCon US Chicago concludes - New Location: Atlanta, GA, USA, -5:00 - Last Attendee Departure: Unconfirmed 2011-03-17 PyCon US Atlanta concludes - New Location: Santa Clara, CA, USA, -8:00 - Last Attendee Departure: Unconfirmed 2013-03-21 PyCon US Santa Clara concludes - New Location: Montréal, Québec, Canada, -5:00 - Last Attendee Departure: Unconfirmed 2015-04-16 PyCon US Montréal concludes - New Location: Portland OR, USA, -8:00 - Last Attendee Departure: Unconfirmed 2015-04-16 PyCon US Portland concludes - New Location: Cleveland, OH, USA, -5:00 - Last Attendee Departure: 7:59pm local time 2015-04-16 PyCon US Cleveland concludes - New Location: Worldwide, 0:00 - Last Attendee Departure: Unconfirmed - Reference: https://x.com/pycon/status/1126637785455185920 - Note: After PyCon US 2019, the planned conference cycle in Pittsburgh, PA, USA was undertaken on-line for 2020/2021. 2021-10-12 PyCon US Salt Lake City Launched - New Location: Salt Lake City, UT, USA, -7:00 - Reference: https://pycon.blogspot.com/2021/10/pycon-us-2022-website-and-sponsorship.ht… 2023-04-27 PyCon US Salt Lake City concludes - New Location: Pittsburgh, PA, USA, -5:00 - Last Attendee Departure: Unconfirmed 2025-05-22 PyCon US Pittsburgh concludes (Estimated) - New Location: Long Beach, CA, USA, -8:00 While I appreciate and understand that this submission may appear to be a gag/joke, I am sincere in this request and humbly request that it be considered with sincerity in kind. -Ee Durbin Director of Infrastructure Python Software Foundation

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Request for Update: Iran's Official Time Zone – No Daylight Saving Time Since 2023
by Khalil Kharazi May 19, 2025

May 19, 2025

Dear Time Zone Database Maintainers, I hope this message finds you well. I am writing to bring your attention to an important legal update regarding the official timekeeping policy of the Islamic Republic of Iran. In March 2022, the Iranian Parliament passed legislation to permanently abolish Daylight Saving Time (DST), effective from March 2023. As a result, Iran now observes a fixed time zone of UTC+3:30 throughout the entire year, with no forward or backward clock shifts. This change is now fully implemented across all provinces and official systems within the country. However, it has come to our attention that some international platforms, time services, and applications may still reflect outdated DST rules for Iran, which can lead to errors in scheduling, communication, and automation. Given the widespread reliance on the IANA Time Zone Database (tzdata) by global operating systems and applications, we kindly request that you verify and reflect this official update in the relevant database records (Asia/Tehran) to ensure accurate representation of Iran’s current time zone policy. Should you require further documentation or references to the legislation, I would be glad to provide official sources or translations as needed. Thank you for your attention to this matter and for your continued efforts in maintaining a reliable and globally synchronized time zone system. Sincerely, [Khalil Kharazi]

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Proposed correction for zone.tab and Link: Europe/Uzhgorod to Europe/Uzhhorod
by Sorel Si May 17, 2025

May 17, 2025

Dear tz database maintainers, I would like to propose a correction to the spelling of the Ukrainian city Uzhhorod in the tz database. Currently, the city is referenced as "Uzhgorod" in `zone.tab` and as a Link target: In `zone.tab`: UA +4837+02218 Europe/Uzhgorod Zakarpattya west Link definition (in the `europe` data file): Link Europe/Kyiv Europe/Uzhgorod The spelling "Uzhgorod" (with a 'g') appears to be a transliteration from the Russian language form of the city's name ("Ужгород"). However, Uzhhorod is a city in Ukraine. The official Ukrainian name is "Ужгород". According to the current official Ukrainian national system for romanization of Ukrainian Cyrillic (approved by Resolution No. 55 of the Cabinet of Ministers of Ukraine, January 27, 2010), the Ukrainian letter "г" (which is present in "Ужгород") is transliterated as "h". Therefore, the correct romanized form from Ukrainian is "Uzhhorod". This spelling ("Uzhhorod") is consistently used by official Ukrainian sources, including the Uzhhorod City Council (e.g., uzhhorod-rada.gov.ua) and in national legislative documents. Given this, I propose the following changes for accuracy and consistency with Ukrainian national standards: 1. Update the entry in `zone.tab` to: `UA +4837+02218 Europe/Uzhhorod Zakarpattya west` 2. Update the Link target name to `Europe/Uzhhorod`: `Link Europe/Kyiv Europe/Uzhhorod` This would align the tz database with the official and correct transliteration of the city's name from its native language. Thank you for your time and consideration. Sincerely, Arsenii

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[PROPOSED] Don’t mention iso3166.tab in zone1970.tab comment
by Paul Eggert May 16, 2025

May 16, 2025

* zone1970.tab: Remove mention of iso3166.tab in comment. In FreeBSD iso3166.tab is not installed, which makes the comment confusing in an installed file. Although FreeBSD gets around this problem by editing zone1970.tab, it’d be better if FreeBSD could use zone1970.tab unmodified. --- zone1970.tab | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/zone1970.tab b/zone1970.tab index 36535bdf..f3227405 100644 --- a/zone1970.tab +++ b/zone1970.tab @@ -2,14 +2,14 @@ # # This file is in the public domain. # -# From Paul Eggert (2018-06-27): +# From Paul Eggert (2025-05-15): # This file contains a table where each row stands for a timezone where # civil timestamps have agreed since 1970. Columns are separated by # a single tab. Lines beginning with '#' are comments. All text uses # UTF-8 encoding. The columns of the table are as follows: # # 1. The countries that overlap the timezone, as a comma-separated list -# of ISO 3166 2-character country codes. See the file 'iso3166.tab'. +# of ISO 3166 2-character country codes. # 2. Latitude and longitude of the timezone's principal location # in ISO 6709 sign-degrees-minutes-seconds format, # either ±DDMM±DDDMM or ±DDMMSS±DDDMMSS, -- 2.49.0

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opposition to recent time zone change in Paraguay
by Paul Eggert May 6, 2025

May 6, 2025

An article last week in El Nacional reports ongoing public opposition to Paraguay's decision to not fall back on March 22, which means sunrise might not occur until after 07:45 in western Paraguay in June. Sen. Blanca Ovelar will promote going back to the old -04/-03-with-DST regime. Other possibilities include changing government schedules for schools, banks, etc. to in effect revert the change for some people. Although I do not expect this to affect TZDB in the short run, we should keep an eye on the situation. Nuevo horario divide al Paraguay. El Nacional. 2025-04-29. https://elnacional.com.py/politica/nuevo-horario-divide-paraguay-n84973

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Re: wrong last-modified timestamp in NIST leap-seconds.list
by Paul Eggert April 24, 2025

April 24, 2025

On 2025-04-24 07:04, Judah Levine wrote: > Your comments have adequately addressed the #$ timetamp definition, which is described in the comments to the file. It has been defined this way for as long as I have prepared the file. There has been no leap second for a long time, and that time stamp reflects that fact. The name of the file is chosen in the same way - it changes only when a new leap event is announced, and now points to a time years ago. > I choose the expiration date of the file so that the list of leap seconds in the file will be correct at least until that date. I use IERS Bulletin C, IERS Bulletin A, and other IERS data to derive that date. It includes a prediction of the evolution of UT1-UTC by the IERS, and is more comprehensive than the simple announcement of a leap second in Bulletin C. > Apart from the recent and continuing drama in the environment here, the file has always been updated long before the expiration date arrives - usually when a new Bulletin C is published. The expiration date is intended to be a safety valve if (and only if) there are more serious problems. I regret that I cannot assure you that the current high level of drama is decreasing. > The leap second file is distributed by FTP. The method has very significant difficulties - it is a long and tedious process to update the file, and there are various reports that it is difficult to access. I don't have a choice about this, at least for now. The other alternatives, such as a web page, would be even more difficult to maintain. Thanks for the heads-up. This makes it clear that the NIST vs IERS leap-seconds.list metadata differences are intentional. I installed the attached proposed patch to TZDB to try to document this in a way that TZDB users can easily understand. If it weren't for the problems with FTP and with NIST's lagging expiration timestamps, I'd prefer the NIST metadata as they're less volatile. For now, though, the proposed patch merely changes commentary, rather than changing the default leap-second data source from the IERS back to the NIST (which was the source for many years, until TZDB release 2024a). Perhaps after things have settled down we can help coordinate the IERS and NIST leap-seconds.list files so that they agree not just about data, but also about the last-modified and expiration timestamps. This would help reduce confusion in the future.

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[PATCH] Don't mention boulder.nist.gov
by Collin Funk April 24, 2025

April 24, 2025

The generated leapseconds file mentions the data can be retrieved from ftp.boulder.nist.gov/pub/time/leap-seconds.list, but the domain no longer resolves. From the Internet Archive for boulder.nist.gov it seems like it was a redirect for nist.gov until it was later deleted. The attached patch removes reference to it. Collin [1] https://web.archive.org/web/20180901000000*/boulder.nist.gov

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[PROPOSED 1/6] * Makefile: Modernize comment.
by Paul Eggert April 21, 2025

April 21, 2025

--- Makefile | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/Makefile b/Makefile index 2130582c..502fe2fa 100644 --- a/Makefile +++ b/Makefile @@ -10,10 +10,11 @@ # To affect how this Makefile works, you can run a shell script like this: # # #!/bin/sh -# make CC='gcc -std=gnu23' "$@" +# make CFLAGS='-O2 -DHAVE_GETTEXT=0' "$@" # -# This example script is appropriate for a circa 2024 GNU/Linux system -# where a non-default setting enables this package's optional use of C23. +# This example script is appropriate for a GNU/Linux system +# which needs more optimization than default, and which does not want +# gettext's internationalion of diagnostics. # # Alternatively, you can simply edit this Makefile to tailor the following # macro definitions. -- 2.48.1

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SBOM required for tzdata2025b and tzcode2025b
by Sahil Sharma D April 21, 2025

April 21, 2025

Hi team, Could you please share the SBOM for tzdata2025b and tzcode2025b? Regards, Sahil

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Iran considering reintroducing daylight saving
by Roozbeh Pournader April 11, 2025

April 11, 2025

There's been news today about Iran potentially reintroducing daylight saving. The CEO of Tavanir, the governmental electric power agency, has said that the government is requesting that the parliament let it set daylight saving at its own pleasure, as opposed to the parliament controlling the rules. He estimates that daylight saving would reduce electricity consumption by about 1%, which could be critical since the country is facing energy shortages.

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