Create a review schedule

Create a calendar using the learning date and directly set review intervals. Reflect rest days and save to CSV or ICS calendar file.

Input

Execute directly using the sample value, or try changing the value.

Review interval and first cycle

1 to 12 commas, each 1 to 3,650 days. The learning date should be entered in ascending order.

Criterion for the interval.

Study days and rest days

Dates when no review is possible

One per line in YYYY-MM-DD format. Impossible dates are moved to the next possible date.

Select learning topic

Name (optional)

First learning day

Input backup·restore

Input is not saved or automatically synchronized. Refreshing returns a sample value. JSON backup includes the name and all inputs. Restoration replaces the current input.

This tool: Import JSON backup (up to 1MB)

Result

Check the result using the example value.

Copy, share, and include name in file

The default output uses item numbers. If “Include name” is enabled, the content and file name are included.

ICS is a daily schedule file. Copy it directly into the calendar. No automatic alerts or synchronization are provided, and repeated imports may cause duplicates in the calendar.

Calculation criteria and usage method

Generate calendar files with date tables and calendars for learning topics based on user-defined review days and intervals.

Based on learning date: Learning date + first review date · Based on previous review date: Actual previous review date + interval

Input example

For a topic studied on 2026-10-05, enter 1, 3, and 7. Counting from the study date gives 10-06, 08, and 12. Counting from the previous review date accumulates the intervals, giving 10-06, 09, and 16. Move rest days to the next available day. With previous-review-date counting, start the next interval from the actual shifted date.

How to use

Use the provided example or modify the settings and selected items. Add items to enter multiple evaluations, textbooks, and topics in order.
Click to create a review schedule. Incorrect inputs are directed to the relevant item and field.
Check the result and save as CSV. You can import the plan as ICS if needed. If you want to continue input, save a separate JSON backup.

Limitations and interpretation

The interval is a user-defined plan. It does not guarantee learning effectiveness or optimal review timing. Up to 50 topics and 12 intervals are generated for 3,650 days after learning. Impossible dates are shifted forward, and overlapping reviews are maintained separately.

Frequently Asked Questions

Are 1·3·7 days the recommended interval with verified effectiveness?

Public example showing the input method. It creates a date with the desired spacing directly, but does not predict memory retention or optimal spacing. It does not automatically adjust the cycle based on recall responses like Anki.

What happens if two reviews occur on the same day due to the weekend?

Each scheduled date based on the learning date is moved to the next possible day, so reviews of the same topic may overlap. Overlapping sessions are not deleted; they are retained with instructions. Compare plans by changing the cycle or day, or based on the previous review date.

Can notifications or automatic changes be added when placed in the calendar?

Directly import the ICS file for the daily schedule. Set alerts and actual import actions in the calendar you use. Changes to input will not automatically update the existing calendar, and repeated imports may cause duplicates in the app.

Calculation criteria and reference materials

IETF RFC 5545 — iCalendar
Schedule start/end, full-day date, repeat date, and UTF-8 content line
Anki — recall response and next review
Difference between review based on response and fixed interval plan set by user. This tool does not implement automatic cycle adjustment for Anki or predict learning effectiveness.

Verification of calculation criteria: 2026-10-03 · Calculation·verification principles · Report errors