Last week, at a social event for senior bankers, I found myself standing in a circle with six men making small talk. As I looked around the group, I noticed that five were clutching tumblers of sparkling water, while only one had joined me in accepting a flute of cold champagne offered by a waiter in a tailcoat.

I made the mistake of remarking on the abstemiousness of the group – with the result that a desultory conversation struck up about everyone’s dry January. After a while, the man with the champagne glass declared that he had given up something much harder than alcohol.

His resolution was to abstain from excessive work, not just for 31 days, but for life. He was fed up with pointless meetings and of emailing at 11pm. For the past three weeks, he had achieved just as much as before but on average had worked no more than seven hours a day – and spent the rest of his time enjoying himself.

There is nothing extraordinary about this. It makes perfect sense – work expands to fill the time available, and all that. And he is senior enough to dictate his own schedule.

The reason I make so much of this story is that it may be the swallow I have been waiting for. For the past two decades, overpaid professionals have been stuck in an eternal winter of working around the clock – and seeing it not only as normal but as impressive.

Yet here was someone at the top of a competitive, workaholic industry, trying to make himself seem bigger in the eyes of his peers not by saying how much he worked but how little.

It is possible that this is the beginning of something big. Bertrand Russell and John Maynard Keynes both predicted this in the 1930s. It has been a long time coming but maybe it is happening at last.

Last year, I spent a couple of months making a radio documentary about overwork. I went around interviewing people who choose to work all the time and to experts who had studied the phenomenon. What I found was roughly what I had expected: that professionals work long hours for four reasons.

Some do it out of competitiveness or to keep up with the Joneses. Some do it because they are inefficient and spend so much time at work cyber-skiving they have to stay late to get the job done. A few do it because they love the rush that comes from work – it can be so much easier and more gratifying than real life. Almost all do it, though, at least in part, for the status that goes with it. We are what we do – and the more we do, the more we are.

However something I didn’t expect emerged from an interview with the author Margaret Heffernan. She told me that in elite executive circles in the US, things are beginning to change. Just as it is vulgar to boast about how much you consume, it is now becoming vulgar to boast about how long you work. There is a vanguard of people, she claimed, who were starting to make the sort of boast my banker was making. Short hours equal high status.

At the time I liked her theory but saw no signs of it being true. Instead, what I saw were the friends of my children starting out in consulting and the law. Not only did they seem to work longer hours than ever, they looked down on anyone who left work at 6pm. But now I’m wondering if Ms Heffernan might be right.

For years, employers in Sweden (a country that was never a fan of overworking) have been experimenting with the six-hour day. There are signs that workaholic Anglo-Saxons are looking on with approval rather than superiority.

The Independent newspaper last week ran an online poll asking whether a similar experiment in Britain would make everyone more productive and happier. About 95 per cent said it would. Agent, a marketing company in the UK, has even put it to the test in an experiment that has just had a rapturous write-up in the US magazine Fast Company.

I’ve completed an interesting test of my own, looking at profiles of executives, bankers and lawyers on a dating website. Each was asked to say how much they worked every week. I couldn’t find a single one admitting to working more than 40 hours.

It is, of course, one thing to be boasting on a dating website to potential partners (who presumably don’t want to date someone who never leaves the office) about how much spare time they have. But what about to colleagues? Was my banker a weirdo or a trendsetter?

As he spoke, I studied the faces of the water-swilling men he was addressing. One snorted and said: “Good luck with that,”, but the other four eyed him with what looked like resentment laced with pure envy. In other words, his boast worked magnificently.