I Thought It Would Take 30 Minutes

02

Nothing gets stuck in the plan

You sit down to put together a one-page report or finish a class assignment. You just need to open your materials, pull out the key points, and polish the sentences. After a quick run-through in your head, 30 minutes seems like plenty of time.

But once you start, you have to find the materials you need, double-check the numbers, and revise sentences you have already written. By the time you click submit, well over an hour has passed. You seem to remember something similar happening last time, yet when you schedule the next task, you write down 30 minutes again.

Before making that estimate, try adding one question: ‘How long did it actually take me to finish something similar last time?’ Pause the mental preview of what you are about to do and look at a record of something you have already finished.

03

Last time’s delays keep becoming exceptions

The tendency to make optimistic predictions about when you will finish, even after similar tasks have taken longer in the past, is called the planning fallacy. In a 1994 study by Buehler and colleagues, university students predicting when they would finish assignments focused mainly on how the work would unfold, rather than on their past experience.

In everyday life, it is easy to explain why something ran late last time. The materials arrived late, someone requested changes, or you had an unusually hard time concentrating. Those problems seem unlikely to happen this time, so they disappear from the schedule. But some of the searching, checking, and revising may be part of this task too.

It is useful to picture the sequence of steps when you plan. Putting the time a previous task took alongside those steps gives you something concrete to check for work you may have left out.

04

One recorded number, rather than a memory

The memory that ‘it took about an hour last time too’ may differ from the actual record. In experiments by Roy and colleagues in 2008, participants who received information about actual task durations estimated the time for similar tasks more accurately than those who did not. One small way to apply that finding in everyday life is to check a recent record of your work.

If you have a timer log or a note with both the start and finish times, open it. If you have no record, start by writing down those two times for your next task. The timestamp on a sent email can tell you when you finished, but not how long the work took.

Choose a recent task with a similar amount of work and a similar process, rather than the day you finished fastest. If your assignments vary too much to compare easily, you can start recording the time for one recurring part, such as finding photos for a presentation. Use that record to estimate the photo search, rather than the whole assignment.

05

Bring last time’s 70 minutes into this plan

Suppose you started a summary assignment at 2 p.m. last time and submitted it at 3:10 p.m. It took 70 minutes from start to submission. If you have a similar amount to read and write this time, start your scheduling with those 70 minutes in view.

If you have already read the materials this time, part of the work may take less time. If you need to create a new table, you may need more. Adjust based on what has changed, rather than on the feeling that ‘I think I can do it faster this time.’

Make sure the record covers the time you need to plan for. If focused writing took 40 minutes, but checking, revising, and submitting brought the total to 70 minutes, the latter is a better fit for a submission schedule.

If you took a long break or did something else in the middle, add a note such as ‘70 minutes from start to submission, including a 15-minute phone call.’ That way, you will know what the number includes when you look at it next time. If messages, calls, or breaks often interrupt your work, consider whether they are likely to happen again instead of assuming there will be none this time. Last time’s duration is a starting point for thinking about the time you need now, rather than a fixed answer to copy.

06

Start with one recurring task

You do not need to time everything in your day or build a detailed timetable from the start. One task you do often, such as putting together reports or writing assignments, is enough. Once it feels familiar, you can try it for everyday activities such as preparing a meal.

When you finish, record how long the task actually took this time too. If it differed greatly from your estimate, write one line about a step you missed or a condition that changed, rather than scolding yourself for getting it wrong. If you forget to record a task one day, start again next time. Today’s goal is not to predict every finish time exactly. It is to look at an actual record once before writing down your estimate.