Time Blocking vs Backward Planning
Published .
Time blocking tells each hour what to do. Backward planning tells you which work deserves an hour at all. Here is how they differ and how to run them together.
Use the free tool: the reverse planner
Time blocking splits your working hours into blocks on a calendar, each assigned to one activity. Backward planning starts from a goal written as finished and works back through milestones to the step you need today. Time blocking answers when. Backward planning answers what. A full calendar of the wrong work is still the wrong work.
The short answer
Use time blocking when your problem is a day that gets eaten by email, meetings and small requests. Use backward planning when your problem is a goal that never moves, even on busy days. Most people with a goal need both: plan backward once a week, then block one slot a day for the step that came out of it.
Side by side
| Question | Time blocking | Backward planning |
|---|---|---|
| Starts from | Your calendar and task list | The goal written as done, with a date |
| Main output | A day split into labelled blocks | Milestones back to one step for today |
| Time horizon | Today, sometimes this week | The goal date back to today |
| Answers | When will I do this? | What should I do next? |
| Best for | Protecting focus from interruptions | Moving one big goal a step at a time |
| Main risk | Blocks that overrun, or fill with the wrong work | A plan with no slot in the week |
What time blocking is
Scheduling work in blocks is an old idea. Cal Newport, a computer science professor and the author of Deep Work, made it widely known. His Time-Block Planner starts from the idea that "a task list is not enough" and that you "should instead partition your working hours into blocks assigned to specific activities." Each planner page also has a shutdown box, so the workday has a clear end (source).
What backward planning is
Backward planning, also called backcasting, flips the usual order. You write the finished goal first, then ask what had to be true one step before it, and keep stepping back until you reach something you can do today. Backward planning covers the method in full.
What the research says, carefully
- We underestimate how long things take. Roger Buehler, Dale Griffin and Michael Ross (1994) asked 37 students when they would finish their thesis. The average guess was about 34 days. The average actual time was about 56 days, and only about 30 percent finished by their own estimate. Even their worst case guesses were too short on average (source). Time blocks built on optimistic estimates will overrun. Small, single step blocks give the estimate less room to go wrong.
- When and where plans help. Peter Gollwitzer and Paschal Sheeran (2006) pooled 94 tests of if-then plans, which name when and where you will act. These plans had a medium to large effect on reaching goals (source). A time block is close to a when and where plan for one step. See implementation intentions.
- What no one has tested. We found no study that compares time blocking with backward planning head to head. The case for combining them is a reasoned one: one picks the step, the other gives it a time.
Treat these findings as a guide, not a promise. This is a planning habit, not medical advice.
When time blocking is the better tool
- Your days fill with messages and meetings, and focused work keeps getting pushed out.
- You already know what matters, but you never seem to have the time for it.
- You want a clear end to the workday.
When backward planning is the better tool
- You have a goal with a finish line, and you are not sure what the next step is.
- Your calendar is full and well run, but the big goal has not moved in months.
- You keep planning tasks that are busy but do not lead anywhere.
How to use both with reverse journaling
- Write the goal as done. Past tense, with a date: "On 30 April I launched my online shop."
- Plan backward once a week. From the finish line, step back to this month and this week. Pick three steps for the week.
- Block one slot a day. About 45 minutes for today's step. Put it where your day is calmest, often first thing.
- Size the step to the block. If it will not fit, cut it in half until it does.
- Log it tonight. One line on your done list. If the block got moved, write that too, and move the step, not the goal.
Example: one week, two ways
Priya wants to open an online shop for her ceramics by spring.
- Time blocking only: her week is fully blocked. Client work, email, admin, a block called "shop stuff" on Thursday. Thursday's block goes to photographing three mugs she already sold. The shop is no closer.
- Goal written as done: "On 30 April I launched my online shop with 12 pieces."
- Backward plan for this week: pick a shop platform, write the about page, list the 12 pieces.
- Daily block: 7:30 to 8:15 each weekday, one step per block.
- Friday's log: "Platform chosen. About page drafted. List of 12 pieces done."
The calendar was full both weeks. What changed is that each block held a step that came from the finish line.
Where this fits in Reverse Journaling
Reverse Journaling starts with the goal written as done, names the obstacle, plans back to today and ends each day with a done log. The daily step runs as a 45 minute sprint. If you already time block, keep your calendar, and give one block a day to the step your backward plan picked. The weekly review is a good place to redo the backward plan.
Try it now
Write one goal as done, with a date. Ask what you need to have finished by Friday for that to happen. Then open your calendar and block 45 minutes tomorrow for the first piece of it.
Questions
What is the difference between time blocking and backward planning?
Time blocking assigns each part of your day to a specific activity on a calendar. Backward planning starts from a finished goal and works back to the step you need today. Time blocking decides when. Backward planning decides what.
Who made time blocking popular?
The idea of scheduling work in blocks is old, but Cal Newport, a computer science professor and the author of Deep Work, made it widely known. His Time-Block Planner argues that a task list alone is not enough and that working hours should be split into blocks assigned to specific activities.
Why do time blocks keep overrunning?
Most people underestimate how long tasks take. In a 1994 study, students guessed they would finish their thesis in about 34 days on average. It took about 56, and only about 30 percent finished by their own estimate. Plan each block around one small step, and leave room to move blocks when the day changes.
Can I use time blocking and backward planning together?
Yes. Plan backward from the finished goal once a week to find this week's steps. Then time block one slot a day, about 45 minutes, for today's step, and log what you did at night.
Do I need to block every minute of my day?
No. Full day blocking suits people with control over their calendar. If your day is full of meetings or care duties, one protected block for your goal step is enough to start.