Don't Break the Chain Calendar

A don't break the chain calendar is a wall calendar for one habit: mark every day you do it and never leave a gap. Tap each day below and the chain draws itself, one link a day. Print it at A4, Letter or A3, or save a streak card to share.

Free, no signup. Your habit and your marks are saved in this browser. New to the method? Read how don't break the chain works.

Your one habit

Current chain

Longest chain

Days marked

Week starts

Your streak card

An image of your chain to send to whoever is keeping you honest. It updates as you mark days.

Print your wall calendar

The sheet below is exactly what comes out of the printer, laid out at the true size of the paper. Put it where you will see it every day.

Layout

Paper

Month Year

To save a PDF instead of printing, choose Save as PDF as the destination in the print dialog. In the same dialog, choose the same paper size, set margins to None, and turn on background graphics if the chain comes out blank.

How the chain is counted

A day is marked when you tap it and unmarked when you tap it again. Days are calendar days in your device's own time zone, so today ends at your local midnight. A day that has not happened yet cannot be marked.

The current chain counts back one day at a time from today, for as long as every day is marked. If today is not marked yet, it counts back from yesterday instead, because the chain is still alive until today is over; it breaks only when a whole calendar day passes with no mark. The longest chain is the longest run of back-to-back marked days anywhere on the calendar, and the total is every marked day. Breaking a chain resets the current chain and nothing else. Day gaps are counted on the calendar, not in hours, so a change to or from summer time never splits a chain.

On the calendar, two marked days that sit side by side in the same week are joined by a link. A chain that runs from the last day of a week into the first day of the next is drawn leaving one row and entering the next, and the same happens across the end of a month. Each link is drawn with a small wobble so it looks marked by hand; the wobble is worked out from the link's date, so the same chain looks the same every time you open it. The 7, 30, 100 and 365-day moments the page marks are round numbers we chose, not findings.

The printable sheet is drawn at the true size of the paper: A4 is 210 by 297 millimetres, US Letter 8.5 by 11 inches and A3 297 by 420 millimetres, with a millimetre taken as 96 divided by 25.4 pixels, the CSS definition. The year layout puts twelve months on one page; the month layout gives each day a box. Your habit and your marks are saved in this browser's local storage, and there is no account.

The method is older than this page and has not been tested as such. What has been tested is progress monitoring in general: in a 2016 meta-analysis of 138 experiments, prompting people to monitor their progress improved goal attainment (d = 0.40), with larger effects when progress was reported or made public and when it was physically recorded. And in seven studies of logged streaks, an intact streak led to more follow-up than a broken one, a gap that shrank when the streak could be repaired — which is why this calendar keeps your longest chain and total days when the current chain breaks.

Where these numbers come from

1. Jerry Seinfeld's Productivity Secret — Brad Isaac, Lifehacker, 2007
2. Seinfeld Productivity Myth (quotes Seinfeld's Reddit Q&A reply) — Jake Shaw, absent.org, 2014
3. Does monitoring goal progress promote goal attainment? A meta-analysis of the experimental evidence — Harkin B, Webb TL, Chang BP et al., Psychological Bulletin 142(2):198–229, 2016 (PubMed)
4. On or Off Track: How (Broken) Streaks Affect Consumer Decisions — Silverman J, Barasch A, Journal of Consumer Research, 2023

Nothing on this site is medically reviewed. Every figure above was read out of the code that runs on this page, and where a number is our own judgement rather than a published one, the note says so and cites nothing. Method last checked 28 September 2026.

One habit, one calendar, one chain

A don't break the chain calendar is a wall calendar for one habit. Every day you do the habit, you mark the day. After a few days the marks form a chain, and from then on your only job is to keep it going. That is the whole method: one habit, one mark a day, and one question — did you do it today?

The story attached to it says a young comedian asked Jerry Seinfeld for advice and was told to hang a calendar with the whole year on one page, and to put a big red X over every day he wrote. The story comes from a 2007 Lifehacker post by the software developer Brad Isaac. In a Reddit Q&A Seinfeld is quoted as calling it "the dumbest non-idea that was not mine", so treat the name as a label rather than a credit. The method is the same whoever thought of it.

Why a wall and not only a phone: in a review of 138 experiments, people who were prompted to monitor their progress reached their goals more often, and the effect was larger when the progress was physically recorded or made public. A calendar on the wall is both, and you see it without having to open anything. No study has tested the chain calendar itself, so read that as a reason it may help rather than proof that it will.

Two things decide whether the chain survives a month. The first is size: make the daily minimum small enough for your worst day — a hundred words, ten minutes of walking, one page — and do more when the day allows. The second is what you do after a break. Start a new chain the next day. The calendar keeps your longest chain and every day you marked, because those days still happened.

The full guide to the don't break the chain method covers choosing the habit and the common mistakes, and what to do when you break a streak covers the day after. For how long a daily habit takes to feel automatic, the habit formation calculator draws the published ranges.

Frequently Asked Questions

What is a don't break the chain calendar?

A wall calendar for one habit. Each day you do the habit, you mark the day. After a few days the marks form a chain, and your only job from then on is to not break it. This page draws the chain for you: tap a day and a link joins it to the day before.

Did Jerry Seinfeld invent the don't break the chain method?

Probably not. The story comes from a 2007 Lifehacker post by the software developer Brad Isaac, who wrote that Seinfeld gave him the advice. In a Reddit Q&A Seinfeld is quoted as calling it "the dumbest non-idea that was not mine". Whoever thought of it, the method is the same: one habit, one mark a day.

How does the chain count on this page?

Tap a day to mark it and tap it again to take the mark off. You can mark today and any earlier day, but not a day that has not happened yet. Marked days next to each other are joined by a link. The current chain counts back from today, or from yesterday if today is not marked yet, because the chain only breaks once a whole day has passed without a mark.

Where are my marks saved?

In this browser, on this device. There is no account, so the chain does not follow you to another phone or computer, and clearing your browser data clears it. To keep a copy, print the calendar with your marks on it or save the streak card.

What size does the printable calendar come in?

A4, US Letter or A3. Pick one and the sheet is redrawn at that paper's true size. The year layout puts all twelve months on one page, like the wall calendar in the original story; the month layout gives each day a big box to cross off. Choose the same size in your print dialog and set margins to None.

How do I save the calendar as a PDF?

Press the print button and choose Save as PDF as the destination in your browser's print dialog. Set margins to None, because the margin is already drawn into the sheet, and turn on background graphics if the chain comes out blank.

What should I do when I break the chain?

Start a new one the next day. The days you marked still happened, and the calendar keeps them: your longest chain and your total days marked do not reset. It is worth treating the break as a gap rather than an ending. In seven studies of logged streaks, seeing a broken streak made people less likely to go back to the activity, and less so when the streak could be repaired (Silverman and Barasch, 2023).

Does the don't break the chain method work?

No study has tested the calendar itself. It rests on a finding that has been tested: in a review of 138 experiments, people who were prompted to monitor their progress reached their goals more often, and the effect was larger when the progress was physically recorded or made public (Harkin and colleagues, 2016). A calendar on the wall does both. Read that as a reason the chain may help, not proof that it will.

Keep the chain on your phone with Aura

Aura checks a habit off in one tap, keeps the streak for you, and shows every day you kept it on a grid — with a reminder at the time you choose.