15-30-60 min timeboxes
Standardise your small-medium-large
TLDR: standard timebox sizes of 15, 30 and 60 minutes make the most sense
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During a talk I gave last week, I was asked about how to size timeboxes. I often get this question. (Note: box-sizing is chapter 12 of Timeboxing.)
The 60-minute hour facilitates many combinations since 60 is divisible by very many numbers: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, and 60.
(This is not a coincidence but was deliberately chosen by the Sumerians and Babylonians; notice, too, that 24 — the number of hours in a day — also boasts an unusually high number of factors.)
We tend to have meetings on the hour, so any version of a timeboxing with box sizes that don’t stack up to an hour just isn’t going to work.
I use 15-30-60. The arithmetic is easy. Quarter-past, half-past, quarter-to and on-the-hour are all very familiar time checks. There are just three choices, so there’s little cognitive overhead in making the decision. The administrative burden of creating, labelling and potentially moving a timebox is not worth it for tasks of less than 15 minutes.
I’ve noticed that my best days (during which I’ve done most and feel happiest) tend to be when I have a lot of 15-min timeboxes.
If you like the Pomodoro technique, then the 15-30-60 accommodates it, with the 30-min timeboxes neatly encapsulating 25 mins of work and 5 mins rest.
As you can see from the image (pixelated as this is my actual calendar and there are some sensitive items), I do sometimes put in a 45-min or even a much longer timebox (usually at the weekend). But the 15-30-60 mantra is useful and applied most of the time.
Timeboxing is flexible — that’s one of its many great qualities. So you can pick your own unit sizes. But 15-30-60 is my strong recommendation.
Marc
Links you may like
7 days of Timeboxing (the free email micro-course)
Timeboxing, the book (US)
Timeboxing, the book (UK)
Timeboxing, el libro (Español)
Connect with me on LinkedIn (I will say yes!)