In 1930, the economist John Maynard Keynes published an essay titled ‘Economic Possibilities for Our Grandchildren’, in which he anticipated how we would spend our time a hundred years ahead. Keynes predicted that future generations would enjoy such an improved standard of living that they might work just fifteen hours a week. In this ‘age of leisure’ it would become a ‘fearful problem’ for ordinary people to decide how to fill their time, he wrote.

The year 2030 is almost here, and needless to say things aren’t panning out quite as Keynes thought. Most people of working age would probably say that they are working more hours than past generations, not fewer. We’re inundated with media stories about how we’re not getting enough sleep, not spending enough time with our families and whiling away our days glued to screens. There’s just no time to stop and think any more.

But is that true? For researchers, it’s quite difficult to accurately measure what people do with their time. Conventional survey questions such as ‘How many hours last week did you spend working?’ generate unreliable answers because it’s unclear which activities should be classified as ‘work’ and because people often give inaccurate estimates or exaggerate how much they were working in order to support their ideal of who they want to be. One solution lies in time-use diaries, in which researchers typically ask people to record exactly in ten-minute blocks what they are doing, where they are, who they are with and how much they are enjoying it, for all 1,440 minutes of the day.

The BBC created the first major collection of UK time-use diaries in 1961 in order to help plan radio and television schedules. In the 1990s, academics and statisticians in the UK and elsewhere began to run regular, nationally representative time-use surveys. The Centre for Time Use Research at University College London has amassed a unique collection of time-use diaries from over twenty-five countries, including approximately one million days of data. This unique information bank forms the basis for the illuminating What We Really Do All Day by Jonathan Gershuny and Oriel Sullivan, co-directors of the centre, and their colleagues. The book draws most heavily on the latest UK time-use survey, carried out in 2014–15. It provides a fascinating insight into how we spend our time now and how patterns of time use have changed – which, in short, is much less than you might think.

In one analysis, the authors first divide time use into nine distinct activities: paid work and education; unpaid cooking, cleaning or DIY; out of home leisure and recreation; exercise; television, audio and reading; leisure at home; shopping; childcare; and sleep, personal care or eating. They then add up the time spent on each of the activities and average it across the population. The results present a picture of what the nation did in a typical twenty-four hours in 1961, 1984 and 2015. A glance at the graphs reveals conspicuous changes, such as the gradual disappearance of consistent weekday mealtimes. In 1961, 80 to 90 per cent of people were eating breakfast, lunch and dinner at regular times; by 2015, this pattern had mostly vanished, with more people eating and snacking throughout the day.

The book is brilliant at busting myths about how we spend our time. Despite huge demographic and societal changes over the last few decades and the unfolding of the digital revolution, the diaries suggest that our use of time has, surprisingly, undergone no vast transformation. The total amount of time we spend at work (paid and unpaid), at leisure or asleep has changed relatively little in fifty years − certainly ‘much less than was expected by the futurologists of the 1960s’, the authors write. As already mentioned, people tend to overestimate the amount of time they spend at work. In surveys, men working full time report that they work an average of 42.9 hours per week and women 39.3 hours. UK time-use diary data from 2014–15 suggests that they actually work 40.2 hours and 37.3 hours respectively. (The data also shows that those who spend the most time working are single parents and parents with full-time jobs.) Similarly, surveys suggest that we overestimate the length of time we exercise by as much as double.

When the data is broken down by gender or socioeconomic status, things get interesting. It’s striking how differently men and women use their time. The graph for an average weekday in 1961 shows that the vast majority of men were doing paid work from nine to five, as convention dictated, whereas women were doing far less paid work and more housework. By 2015, the weekdays of men and women had become more similar, though differences remained. The amount of time women spend in paid work has gone up and the amount of time they spend doing domestic work (cooking, cleaning and laundry) has dropped substantially, from 189 minutes per day on average in 1984 to 109 minutes in 2015. Men, by contrast, spent 22 minutes doing domestic work in 1984 and 48 minutes in 2015. Men spend a little more time now on childcare too, but again far less than women. These and other statistics in the book add up to a rather depressing reminder of the stubbornness of the gender divide.

One of the most fascinating myths the authors take on is the idea that people today are much busier than they were in the past. Certainly, life feels pretty overwhelming from where I’m sitting, with a full-time job, children and an arm’s-length list of chores that never get done. The media propagates the idea that we’re always multitasking, and that computers and phones have demolished the boundaries between work and home. Time-use data offers one way of examining objectively whether or not we’re really busier than our parents once were.

The authors find little proof of increasing busyness among the population. Yes, as expected, people were spending far more time on digital devices in 2015 than they were in 2000. But the data provides little evidence that people now spend more time multitasking or that they’re switching more often from one activity to another, which might make our time seem fragmented and frantic.

The perception that we’re all super busy might have grown, the authors say, because of the way that certain subgroups of the population who have seen an increase in their workloads – those who are highly educated, in higher-status jobs and in dual-career households with small children – are more likely to have an influential voice in society and the media and so might have helped to create an impression that everyone is now busier. The authors also propose that people wear their busyness as a badge of honour. ‘The words “I’m terribly busy at work” act as a means of status enhancement, signalling importance and indispensability,’ they write.

This book is academic in style and can be dry at times; there isn’t much in the way of a narrative to help the data slip down. It’s also focused mostly on time patterns in the UK, and the few international comparisons offered only take in other wealthy countries. But its insight into what we do is illuminating. It’s impossible not to see your life − and those of your parents and children − reflected in the data or to ponder how far your own days differ from the average. And that makes reading it an excellent use of time.