Commitment check

Everything sounds doable when it is three weeks away. This is a way to check a request against the week you actually have, before the yes leaves your mouth. Fill in a normal week, then add the new thing at the bottom.

The test behind it

The check is one question: would you say yes if this were happening this week, in the week you have just described? If the honest answer is no, a date three weeks out does not change the arithmetic. It only hides it.

Why the future looks emptier than it is

In a series of seven experiments, researchers found that people expect to have more spare time in the future than they have now, and that this expectation is stronger for time than for money. Next month’s calendar looks open because the small things that will fill it have not arrived yet, not because next month is different.

The second problem is the estimate itself. In the studies that gave the planning fallacy its evidence, people’s predictions of how long their own tasks would take were consistently too optimistic, largely because they pictured the plan going smoothly and did not consult how similar tasks had gone before.

What is a rule of thumb here

The padding of one half on top of your estimate is our planning allowance, not a number from either study; the research says estimates run short, not by how much for you. If your past commitments usually took double, use double. The same goes for the three hours a day of basics: change it to match your household.

The numbers also say nothing about energy. A week can have free hours and no capacity left, which is a reason to keep some hours unclaimed on purpose.