TZ History Articles & ResearchDeep dives into the history, anomalies, and mechanics of the IANA Time Zone Database.https://tzhistory.org/en-usHow to Read a tzdb Zone and Rule Line: A Developer's Guidehttps://tzhistory.org/blog/how-to-read-a-zone-line/https://tzhistory.org/blog/how-to-read-a-zone-line/A step-by-step breakdown of tzdb syntax: Zone definitions, Rule transitions, Link aliases, and AT/UNTIL modifiers.Tue, 22 Sep 2026 00:00:00 GMTThe Countries That Abolished Daylight Saving Time, and Those That Brought It Backhttps://tzhistory.org/blog/abolished-and-readopted-dst/https://tzhistory.org/blog/abolished-and-readopted-dst/Why governments repeatedly abandon and resurrect daylight saving time, and how tzdb rules track the political oscillation.Mon, 21 Sep 2026 00:00:00 GMTRussia's 11 Time Zones and a Decade of Temporal Reversalshttps://tzhistory.org/blog/russia-reversals/https://tzhistory.org/blog/russia-reversals/From permanent daylight saving time to permanent standard time: how Russia reorganized its 11 time zones three times in four years.Sun, 20 Sep 2026 00:00:00 GMTThe Curious History of Amsterdam Time: UTC+00:19:32.13https://tzhistory.org/blog/amsterdam-time/https://tzhistory.org/blog/amsterdam-time/How the Netherlands maintained a fractional offset of 19 minutes and 32 seconds for three decades before World War II.Sat, 19 Sep 2026 00:00:00 GMTThe Fractional Offsets Still in Use Today: 15, 30, and 45 Minuteshttps://tzhistory.org/blog/fractional-offsets-today/https://tzhistory.org/blog/fractional-offsets-today/Why several billion people do not observe whole-hour UTC offsets, from India and Iran to Nepal and Chatham Island.Fri, 18 Sep 2026 00:00:00 GMTThe Nation That Skipped a Day: Samoa and the International Date Linehttps://tzhistory.org/blog/samoa-skipped-day/https://tzhistory.org/blog/samoa-skipped-day/How Samoa moved from east to west of the International Date Line twice: repeating the 4th of July in 1892, then erasing December 30 in 2011.Thu, 17 Sep 2026 00:00:00 GMTWatching Standard Time Spread Across the Globe: 1883 to Todayhttps://tzhistory.org/blog/watching-standard-time-spread/https://tzhistory.org/blog/watching-standard-time-spread/How local solar time gave way to coordinated standard time zones, driven by railroads, telegraph lines, and international diplomacy.Wed, 16 Sep 2026 00:00:00 GMTWhat the tz database is and why one text file runs the world's clockshttps://tzhistory.org/blog/what-is-tzdb/https://tzhistory.org/blog/what-is-tzdb/How a public domain collection of plain text files maintained by volunteers coordinates timestamps for billions of devices.Tue, 15 Sep 2026 00:00:00 GMT