At One Place

The last time

36 things that happened once and have not happened since. The last person walked on the Moon in 1972, the last US state was admitted in 1959, the last leap second was inserted in 2016. Each entry gives a date and what actually took place.

Why there is no "years ago" on any of these pages

These pages are built as static files and served without a server, so any computed interval would freeze at the moment of the build and be wrong the following year. A reference page that confidently gives a stale number is worse than one that gives a date and lets you subtract. So every entry gives the date, and a duration appears only between two historical endpoints — the 27th Amendment took 202 years from proposal to ratification, and both ends of that are fixed forever.

Everything, most recent first

Question When What Could change?
When was the last Boeing 747 delivered? 31 January 2023 A 747-8 freighter handed to Atlas Air, the 1,574th built No
When did Microsoft Office last change its default font? 2023 Aptos replaced Calibri No
When did the London Underground last gain a line? 24 May 2022 The Elizabeth line opened No
When were the SI base units last redefined? 20 May 2019 The kilogram, ampere, kelvin and mole were all redefined at once No
When was the last leap second added? 31 December 2016 A second added to the end of 31 December Yes
When was an element last added to the periodic table? 28 November 2016 Nihonium, moscovium, tennessine and oganesson were named, completing row seven Yes
When was the last VCR manufactured? July 2016 Funai of Japan stopped, the last manufacturer in the world No
When was the last telegram sent? 15 July 2013 India's state telegraph service closed, the last large public network to do so No
When did the Space Shuttle last fly? 21 July 2011 Atlantis, landing at Kennedy Space Center on STS-135 No
When did a country last join the United Nations? 14 July 2011 South Sudan, the 193rd member Yes
When did the last typewriter factory close? 2011 Godrej & Boyce in Mumbai stopped making manual typewriters No
When was the last roll of Kodachrome developed? 30 December 2010 At Dwayne's Photo in Parsons, Kansas — the last lab on Earth that could No
When did the tallest building in the world last change? 2010 The Burj Khalifa in Dubai took the title Yes
When did analogue television end in the United States? 12 June 2009 Full-power analogue broadcasting ceased nationally No
When did the number of planets last change? 24 August 2006 Pluto was reclassified as a dwarf planet, leaving eight No
When did Concorde last fly? 24 October 2003, with the last flight of all on 26 November 2003 A British Airways flight from New York to London, then a final ferry flight to Bristol Yes
When was the US Constitution last amended? 7 May 1992 The 27th Amendment, on congressional pay Yes
When was Halley's Comet last visible? 9 February 1986 Its 1986 perihelion, the worst viewing in two thousand years No
When did the prime meridian last move? 1984 The adoption of WGS 84 shifted it about 102 metres east of the Greenwich line No
When was the metre last redefined? 1983 Defined as the distance light travels in 1/299,792,458 of a second No
When did a human last walk on the Moon? 14 December 1972 Eugene Cernan, the last man to leave the surface, on Apollo 17 Yes
When did Britain last change its currency system? 15 February 1971 Decimal Day, when the pound went from 240 pence to 100 No
When did the US flag last change? 4 July 1960 The fiftieth star was added for Hawaii No
When was a US state last admitted? 21 August 1959 Hawaii, the fiftieth Yes
When did the Olympics last award medals for art? 1948 The London Games, the last with art competitions No
When did Vesuvius last erupt? March 1944 A major eruption during the Allied occupation of Italy Yes
When were the Olympic Games last cancelled? 1944 The 1944 Summer Games, awarded to London and never held No
When did the last thylacine die? 7 September 1936 At Hobart Zoo, Tasmania No
When did a European country last change calendar? 1923 Greece adopted the Gregorian calendar, the last in Europe to do so No
When did the last passenger pigeon die? 1 September 1914 Martha, at Cincinnati Zoo No
When was a leap year last skipped? 1900 1900, which was divisible by four and not a leap year No
When did the size of the US Supreme Court last change? 1869 Fixed at nine justices by the Judiciary Act Yes
When did the Union Jack last change? 1 January 1801 St Patrick's saltire was added for the union with Ireland No
When was a letter last added to the English alphabet? The 1500s and 1600s J and U separated from I and V, settling by the seventeenth century No
When did the last ice age end? About 11,700 years ago The end of the Younger Dryas cold period No
When did the Earth's magnetic poles last reverse? About 780,000 years ago The Brunhes–Matuyama reversal No

The streaks that could still end

10 of these are open in the sense that the thing could happen again — a crewed Moon landing, a new UN member, another leap second, another element. Those pages say so, because a page that quietly becomes wrong is the failure mode this whole category invites.

Space

Science and measurement

Countries and borders

Technology that stopped

The natural world

Everyday things

Common questions

When did a human last walk on the Moon?
Eugene Cernan left the surface on 14 December 1972, on Apollo 17. All twelve people who have walked on the Moon did so between July 1969 and December 1972 — a window of forty-one months.
When was a letter last added to the English alphabet?
J and U separated from I and V during the 1500s and 1600s and nothing has been added since. The ampersand was for a while recited as a twenty-seventh letter and was dropped in the nineteenth century.
When was the last leap second?
31 December 2016. In November 2022 the General Conference on Weights and Measures voted to stop inserting them by 2035, because they break computer systems in ways that are hard to test for.