Naming things is hard

Pet peeve: adding up time

One of my pet peeves is the type of argument about saving time which assumes that multiple disjoint periods of time can be added up. For example, this tweet argues that

A lack of commute will give workers the equivalent of 25 extra days a year to do the things that make them happiest.

(Yes, this is from a thread arguing for remote-only work which I am very critical of, and yes, it’s a sales pitch for the author’s company rather than a balanced argument. But let’s put all that aside for a moment.)

The problem is, time doesn’t work that way. You cannot accumulate it. You cannot store a unit of time to be used later, which also means you cannot merge the free time you have right now with other periods of free time later on.

Let’s say you want to cook a meal on Sunday but you realize your day is packed so you won’t have the time. Assuming that cooking would take you one whole hour, you could decide to set your alarm 10 minutes earlier than usual for just one week, which would give you an extra 60 minutes from Monday until Saturday. Does this mean you now have your extra hour on Sunday? Of course not. What you have is 6 times 10 minutes. Which can be nice — you can read a couple of pages from a book, stretch a little, or maybe watch the sunrise. But you cannot cook the meal because that takes one hour of uninterrupted time, which is why this addition just doesn’t add up.

Even if the number of hours saved up by not commuting to work every day numerically adds up to the number of hours in 25 days, saying that these two are equivalent is simply misleading, because it makes the reader think of having 25 extra vacation days.

So be careful when doing math with things that do not behave like numbers. If you can put two and two together, you might just find that when talking about time, 2 + 2 simply equals… 2 + 2.