What is a time cushion?
A time cushion is deliberate empty time left between commitments to absorb overruns. A meeting booked 10:00 to 11:00 with the next at 11:15 has a fifteen minute cushion, and that gap is what stops one delay cascading through the rest of the day.
Why estimates need one
People consistently underestimate how long things take, a bias so reliable it has a name, the planning fallacy. Estimates tend to describe the version where nothing goes wrong, and something usually does. A cushion accepts that rather than arguing with it.
Without slack, a schedule is a chain: one task running twenty minutes over pushes everything after it, so you arrive late to things that had nothing to do with the delay and spend the afternoon apologising.
How much
- Between meetings: 10 to 15 minutes. Enough to finish notes, move rooms and start the next one present.
- Around travel: add 25 percent or more, since travel has the fattest tail of any everyday estimate.
- Across a day: aim to book 60 to 70 percent of available hours. The remainder is not idle, it is what absorbs the day's surprises.
The objection
Unbooked time looks wasteful on a calendar, which is why cushions get filled first. What it actually buys is a schedule that survives contact with a normal day, and the alternative is not more output but the same output delivered late and under pressure.
