➤ Repetition Formula
A spaced repetition system measures how long intervals between two dates will be. For example, if you review for an exam today and plan to review again in two days, and again three days after that, the movement of the review date relies on a set of conditions. Using two different methods, I found a way to push dates forward using checkboxes and select properties with a Notion formula.
How To Push Dates Forward With Notion Checkbox
With checkboxes the user can assign how many days an original date will push forward after each session.
The Scenario
In the example below, everytime a checkbox is ticked, the original date is pushed 3 days. This will only occur at a maximum 3 times with a 9 day gap. Of course, you can add more checkboxes and alter the space between each repetition via a simple formula.
Required properties
Date: This is the original date of review.
Three checkboxes: Labeled Session 1, Session 2, and Session 3
You can always add more checkboxes
Next Review Formula
if(prop("Session 3"), dateAdd(prop("Date"), 9, "days"), if(prop("Session 2"), dateAdd(prop("Date"), 6, "days"), if(prop("Session 1"), dateAdd(prop("Date"), 3, "days"), prop("Date"))))
how To Push Dates Forward With Select Property
Required properties
Date: This is the original date of review.
Three select properties: Labeled Session 1, Session 2, and Session 3
You can always add more select properties
Inside each dropdown menu, each option will instruct the formula to move the original date forward a set number of days. In this example, there are 3 options. You can freely add more.
1 day (red) = poor understanding of material
4 days (yellow) = moderate understanding of material
7 days (green) = great understanding of material
Next Review Formula
dateAdd(prop("Date"), toNumber(prop("Session 1")) + toNumber(prop("Session 2")) + toNumber(prop("Session 3")), "days")
An In-Depth Walkthrough
If you’re unfamiliar with Notion formulas, this walkthrough of the above formulas may be of use: