Spaced Review Planner

How to use it

1. Add what you learned. Write a title you will recognise later. A question works better than a topic name. Add a source link and notes if they help. The date defaults to today.
2. Pick a schedule. Standard (1, 3, 7, 14 and 30 days after you learned it) is the general-purpose default. Exam crunch (1, 2, 4 and 7) fits a test within about two weeks. Long-term (1, 7, 30, 90 and 180) is for things you want to keep for months. Or type your own: up to ten whole days, 1 to 365, ascending.
3. Open “Due today and overdue” each day. For every item, answer from memory first. Say it aloud or write it down, then check your source.
4. Mark it done, or move it to tomorrow. “Mark done” records today’s date. “Reschedule to tomorrow” gives that review tomorrow’s date, and any later review that would now fall on or before it moves out too.
5. Take the dates with you.Download the calendar file and import it. In Google Calendar on a computer, choose Settings, then Import & export, select the file, and click Import. Download a JSON backup too: the plan lives only in this browser.

How it works

Hermann Ebbinghaus published his memory experiments in 1885, learning lists of nonsense syllables with himself as the only subject. Murre and Dros (2015) repeated the procedure with one participant over about 70 hours of learning and found a curve similar to the original: forgetting is steep at first, then flattens.

For long-term retention, reviewing in separate sessions beats cramming. A 2006 meta-analysis by Cepeda and colleagues pooled 839 assessments from 317 experiments and found that the best gap between sessions grew as the time you needed to remember grew. In 2008 the same group taught 1,354 people 32 obscure trivia facts, reviewed them after gaps of zero to 105 days, and tested them 7 to 350 days later. The best gap was about 20 to 40 percent of a one-week delay but only 5 to 10 percent of a one-year delay. Too long a gap cost less than too short a gap.

Retrieving beats rereading. Roediger and Karpicke (2006) had 180 students learn a short prose passage. A week later, students who had studied it once and then taken three free-recall tests, without feedback, recalled 61 percent. Students who had studied it four times, reading it about 14 times in all, recalled 40 percent, and had predicted they would remember more. Five minutes after studying, the rereaders were ahead, 83 percent to 71 percent, so rereading feels like it works. In a 2013 review of ten learning techniques, Dunlosky and colleagues rated practice testing and distributed practice highest, and rereading and highlighting low.

The intervals are heuristics, not magic numbers

The research does not single out 1, 3, 7, 14, 30. Most spacing experiments compare one gap with another, using two study sessions and a single final test, on verbal material such as word lists, facts, and short passages. What they do support is narrower: the longer you need to remember something, the longer the gap before the review should be. The presets reflect that: Exam crunch ends at day 7 and Long-term runs to day 180. Whether each gap in a sequence should be longer than the last is less settled. Cepeda’s 2006 review concluded that expanding intervals rarely seem to produce much harm for recall after long delays, but that there is insufficient data to say whether they help. Treat the schedules as sensible defaults and adjust them to your deadline.

Dates are counted from the day you learned the item. If you finish a review late, later reviews that would now land on or before it are pushed out so they stay spaced after it. That rule is ours, not a research result. The planner lists one review per item, so a lapsed item does not ask for five in one sitting.

The calendar file follows RFC 5545: each review is an all-day event whose end date is the following day, because event end dates are exclusive.

Tips for reviews that work

• Retrieve before you re-read. Close the notes and write the answer first, then compare.
• One idea per item. “Chapter 4” gives you nothing to retrieve. “What problem does a B-tree solve?” does.
• Use AI to quiz you, not to explain. See how to learn with AI without fooling yourself.
• Give it a fixed slot. Tie it to your weekly review or another routine you already keep.

What it does not do

• It sends no reminders or notifications. Open it each day, or import the calendar file and set alerts in your calendar app.
• It does not quiz you or grade your answers. You do the recall, then mark the review done.
• It does not adapt the schedule to how well you remembered. Every item follows the dates you chose, apart from the late-review rule above.
• It has no accounts and no sync, so another device starts empty until you import a backup.

Frequently asked questions

Is my data uploaded anywhere?

No. The planner’s own code makes no network requests, and your items are never sent to us. They are saved in this browser’s local storage under the key lhp.spacedReview.v1, so clearing site data deletes them. There is no account or sync: use the JSON backup to restore a plan or move it. The privacy policy covers the site-wide scripts this page also loads.

Can my plan disappear?

Yes. Clearing site data removes it, and so does a private window when it closes. Safari also deletes a site’s script-writeable storage, which includes localStorage, after seven days without you interacting with the site, and exempts Home Screen web apps. Gaps between reviews can be longer than that (Long-term goes from day 30 to day 90), so download a JSON backup after you add items. Browser policies change.

What if I skip a few days?

Open “Due today and overdue”. Each item appears once, with how many days it is late. Do the review and mark it done. Later reviews of that item are re-spaced so they do not pile up.

Which schedule should I choose?

Pick by when you need to know it. A test in ten days suits Exam crunch, something you want to keep for months suits Long-term, and Standard is the default.

Will importing the calendar file twice create duplicates?

Each event keeps the same ID between exports, which calendar apps can use to recognise it, but apps differ. If you see duplicates, import into a calendar of its own, so you can delete that calendar and import again. Google Calendar lets you choose the calendar during import.

Can I set a time or an alert?

Reviews are all-day events, so they have no time. Add a time or an alert in your calendar app if you want a reminder.

Related guides

• Build a Daily Study Habit That Survives Busy Weeks

  Keep showing up and keep remembering: a 10-minute minimum session for bad days, a weekly plan, and review dates set by your test date, with the evidence and its limits.

• How to Stop Losing Context While Browsing: A Tab Note-Taking Workflow

  Attach notes to the page where the thought happened: a scope decision table, a three-second capture routine, and a ten-minute weekly sweep template.

• Turning Internal Docs into Audio: When It Works, When It Doesn't

  What research says about listening versus reading, which documents suit audio, plus a production checklist, a scenario-quiz template, and a measurement plan.

• Zettelkasten, PARA, or Plain Folders? Choosing a Note Method

  Match Zettelkasten, PARA, Cornell notes, a daily log, or search-first folders to your kind of work, then test one in two weeks with a timed find test.

Sources

• Distributed practice in verbal recall tasks: A review and quantitative synthesis — Cepeda et al., Psychological Bulletin 132(3), 2006.
• Spacing effects in learning: A temporal ridgeline of optimal retention — Cepeda et al., Psychological Science 19(11), 2008.
• Test-enhanced learning: Taking memory tests improves long-term retention — Roediger and Karpicke, Psychological Science 17(3), 2006.
• Improving students’ learning with effective learning techniques — Dunlosky et al., Psychological Science in the Public Interest 14(1), 2013.
• Replication and analysis of Ebbinghaus’ forgetting curve — Murre and Dros, PLOS ONE 10(7), 2015.
• Memory: A Contribution to Experimental Psychology — Hermann Ebbinghaus, 1885 (English translation 1913).
• RFC 5545: Internet Calendaring and Scheduling Core Object Specification — IETF, 2009.
• Tracking Prevention in WebKit — WebKit, the section “7-Day Cap on All Script-Writeable Storage.”
• Import events to Google Calendar — Google Calendar Help.