Thoughts on the way we measure time

It just struck me the other day: our main units of time are a hodgepodge of those determined by an external reality and those that are completely arbitrary. And since time is such a central concept to how we organise our lives in the modern world, it makes me wonder how life would be different if we changed the units…

Time units defined by physical reality

  • Year: one (-ish) circumnavigation of the sun by the Earth
  • Month (sort of): approximately one cycle of the moon from full to empty back to full
  • Day: one revolution of the Earth around its axis

Entirely arbitrary time units

  • Hour, minute, second: came from the Babylonians who liked their multiples of six; no connection to physical phenomena
  • Week: possibly also the Babylonians, maybe related to the Genesis story of God creating the world in 7 days; definitely no modern logic

Path dependency

The arbitrary time divisions of hours and weeks are massively influential, invisibly shaping almost every aspect of our lives.

We work for five days and rest for the two which we have designated the ‘week end’. We take holidays that last for a given number of weeks. School terms come packaged in 10-week blocks.

TV shows are (or used to be, before Netflix) designed to fit into a 30- or 60-minute time slot. Work meetings are almost inevitably scheduled for half an hour by default. Important events start on the hour rather than at 2 minutes past.

An alternative world

What if this weren’t the case? What if we could define our own units of time from scratch, based on the logic of the modern world rather than ancient superstitions?

Better minutes and hours

Let’s start by changing our fundamental unit of daily time. Minutes and hours should reflect the most important resource we have available: attention. Adult humans have an effective attention span of around 20 minutes, so let’s make this the new hour. Since we work in a decimal world, may as well divide this into 10 increments.

So our new minutes would be the equivalent of 2 current minutes, and an hour would be 20 current minutes. This makes the switch fairly painless, too: a day now simply lasts for 72 new hours, and if it’s too difficult to change the definition of second (it is one of the SI units, after all), then it’s fine – a new minute has 120 of them.

Better weeks

The main purpose for the ‘week’ time division is to split up our days into those when the majority of people are expected to work vs those when people are at leisure. As such, our new weeks should ideally reflect the best schedule for productive work.

I’m not sure what this is: would we ideally have two days of work followed by one day off, punctuated occasionally by longer breaks? Or would it be better to have longer stretches of work and longer breaks? We would need some more research.

One of the thorny issues would be the conflict in ideal schedules between white- and blue-collar work. I suspect ideal productivity for manual labour would follow a very different schedule to that of knowledge work.

For me personally, a five-day stretch is not ideal for productivity. By the end of the week I am no longer functioning at my peak – Friday is very much more of a transition day into the weekend than a fully productive work day. However, I would easily be able to stay fully productive for three days at a stretch if there were a day of rest immediately after. A 3/1 cycle with a longer break of 3 or 4 days periodically would suit me extremely well, and increase my output.

Existing support for this idea: