Tonight in Glasgow they run a distance Britain officially stopped using in 1966, because people never stopped caring about it

The rest of this edition is about hours nobody counts. So allow me a unit nobody should still be using.

At 8.55 this evening, at Scotstoun Stadium in the west end of Glasgow, they will run a mile. Not fifteen hundred metres. A mile: 1,609.34 metres, an eighth of a Roman mile of a thousand paces, standardised by an Act of Parliament in 1593 for reasons involving furlongs and ploughing.

The mile was on the Commonwealth programme from the first Games in 1930. It was dropped after 1966 and replaced by the 1500 metres, which is the rational choice. The metric system is coherent, internationally legible, and does not require anyone to know what a furlong is. Every argument was on the side of the replacement, and the replacement duly held the programme for sixty years.

This year Glasgow has taken the 1500 metres off the programme entirely and put the mile back. Not added: replaced. The reintroduction was pushed by Sebastian Coe, who called it the quintessential Commonwealth athletics event, and it leaves the mile as the only middle-distance race between the 800 and the 5,000.

It is also the only non-metric distance for which world records are still officially recognised. One survivor, kept alive by nothing more defensible than the fact that people care about it.

Then consider what has happened to that survivor in the last fortnight. On 18 July, at the London Diamond League, Josh Kerr ran three minutes 42.66 seconds and took the world record off Hicham El Guerrouj, whose 3:43.13 had stood since Rome in 1999. Twenty-seven years, beaten by forty-seven hundredths of a second. Kerr had gone into the race calling it Project 222, after the number of seconds he was chasing.

He did not get to 222. He got to 222.66, and the whole point of the story is that the number he was chasing had no external existence at all. Nobody commissioned it. There is no prize attached to 222 seconds. It is a round figure in a unit that Britain formally abandoned for trade in the 1960s, pursued by a man from Edinburgh who decided it would be a good thing to have done.

Kerr ran his heat on Wednesday in 3:58.57 and said afterwards that he wanted as much pressure on him as possible. Jake Wightman qualified in 3:54.05. Neil Gourley is in it. The final closes the athletics programme, and by the time most of you read this the result will exist and I will not have seen it, because this edition goes out before the gun. If you want to know who won, the answer is somewhere else. It is not the part I am interested in.

The part I am interested in is that a Saturday evening in Glasgow will be organised around four laps of an obsolete unit, watched by a full stadium, none of whom have to be there.

This paper keeps asking what people do when they no longer have to work. The rest of today's edition offers one unhappy early answer, which is that a good deal of the freed time goes straight back into minding the machine that freed it. That answer is measured and I think it is right, and it is not the only thing that will happen.

Because the other answer is out there tonight, in the rain if Glasgow runs true, and it looks like this. Given the choice, people do not optimise. They chase a round number in a discarded unit. They keep the race that means something over the race that measures better. They put in the effort precisely where no efficiency argument supports it, and then twelve thousand people turn up to watch them do it.

The mile survived because it was loved rather than because it was sensible. That is not a small finding about the future of work. It may turn out to be most of it.