They sound like the same thing and are often used interchangeably. They are not: one reserves time, the other limits it.
Time blocking reserves time; timeboxing limits it. Time blocking says "9 to 11 is for writing". Timeboxing says "this draft gets 90 minutes, then it is done, finished or not". One protects your calendar from other people; the other protects a task from your own perfectionism.
| Timeboxing | Time blocking | |
|---|---|---|
| Core idea | A fixed budget for one task | A reserved slot for a kind of work |
| The question it answers | How long may this take? | When will I work on this? |
| At the end of the time | You stop and ship, ready or not | You move to the next block |
| Fights | Perfectionism, Parkinson's law | Meetings, drift, competing priorities |
| Typical scale | One task | Parts of the whole day or week |
They stack well. Block Tuesday morning for the report, then timebox each part inside it: 45 minutes for the outline, 90 for the draft. The block guarantees the report gets attention; the timeboxes stop the outline from eating the whole morning.
Giving a task a fixed, non-negotiable amount of time and stopping when it runs out, whether or not the task feels finished. It counters Parkinson's law — the tendency for work to expand to fill the time available.
No. Time blocking reserves calendar time for a type of work; timeboxing caps how long a specific task may take. They are often used together.
Loosely, yes — each Pomodoro is a 25-minute timebox. But classic timeboxing is about finishing a task within its budget, while Pomodoro is about sustaining focus over a series of intervals.