The planning fallacy: why your day never fits

You planned eight tasks. You finished five. The next day you did it again. This is the planning fallacy: people predict task times from the best case, not from what usually happens.

Why it happens

• We imagine the task going smoothly and forget interruptions.
• We plan the work but not the switching between tasks.
• We forget that the day has meetings, meals and breaks in it.

The fix is data, not willpower

Track how long tasks actually take for a week. Divide actual by estimated for each. If the average is 1.4, multiply your next estimates by 1.4. That is the whole trick, and it works because it uses your own history instead of hope.

Add a buffer

Even with good estimates, leave 10–20% of the day empty. Surprises are not exceptions; they are the normal weather of a workday.