The two names get used for each other. They are different tools. Time blocking is a calendar. Timeboxing is a timer.
Time blocking decides in advance when things will happen: 9 to 11 writing, 11 to 12 email. Timeboxing decides how long one thing gets, right now, and starts a timer. One is a plan for the day. The other is a commitment for the next half hour.
| Time blocking | Timeboxing | |
|---|---|---|
| Made when | The night before or the morning of. | The moment you start. |
| Unit | A slot on a calendar. | A block with a timer. |
| What can go wrong | The day does not follow the plan and the plan is abandoned by 10:30. | You do not start. Nothing else can go wrong. |
| What is recorded | What you intended to do. | What you did, with minutes and time. |
| Interruptions | Shift every later slot. | Pause the block, resume, or fail it. |
| Good for | Days with fixed appointments and many people. | Work you control. Studying. Anything you have been avoiding. |
A time-blocked day is a forecast. Forecasts are wrong by 10:30 and the rest of the day becomes a negotiation with a broken plan. A timebox makes no forecast. It only asks one question: what is the next thing, and how big is it? When the block ends, you ask again. The day is built forward from real blocks rather than backward from a plan that did not survive.
They do not compete. Block the calendar for the parts of the day owned by other people: meetings, classes, the commute. Timebox the parts you own. Inside a two-hour calendar slot marked “thesis,” run three timeboxes and a break, and at the end you know what the two hours were.
The app has no day view and no drag-and-drop hours, on purpose. It has a generator: describe the task, pick a tier, the timer starts, and the exact length is rolled inside the tier's range so there is nothing to negotiate. The closest thing to a plan is the queue, which holds up to five blocks and breaks to run back to back. That is a short chain, not a schedule. Everything else is the ledger of what happened.
On the rolled lengths: why you cannot pick the minutes. On the fixed-box method: timeboxing vs Pomodoro.