Missed a Day? Why the Next Day Matters More

Most new habits don’t end on the day you skip them. They end a day or two later. You miss Tuesday’s walk because a meeting ran late, on Wednesday it rains, and by Thursday you’re thinking of the walk as something you used to do.

Both parts of that sequence have been studied, and the skipped day turns out to be the minor one. What people conclude about themselves afterwards does more harm, and that part can be planned for.

What One Missed Day Does to a Habit

The study most people cite on habit formation was run at University College London. In 2010, Phillippa Lally and her colleagues asked 96 volunteers to choose one eating, drinking or activity behavior and do it every day in the same context, such as after breakfast, for twelve weeks. Each day the volunteers rated how automatic it felt. The median time for that rating to level off was 66 days, with a very wide spread: 18 days for the fastest person and an estimated 254 for the slowest.

The finding that gets quoted less often is the useful one here: missing a single opportunity did not materially affect the process. A day off followed by a return didn’t set people back by much. That fits the general picture of habits as the product of many repetitions in the same setting, where one gap is a small fraction of the total.

Lally, P., van Jaarsveld, C.H.M., Potts, H.W.W. & Wardle, J. (2010). “How are habits formed: Modelling habit formation in the real world.” European Journal of Social Psychology, 40(6), 998-1009.

The What-the-Hell Effect

Janet Polivy and Peter Herman, psychologists at the University of Toronto, documented the day-after problem in dieters. In their lab studies, people on a diet who were given a milkshake, and so believed the day’s diet was already broken, went on to eat more afterwards than people who weren’t dieting. Once the rule was broken, sticking to the rest of it seemed pointless. They called this counter-regulation. It also goes by a blunter name: the what-the-hell effect.

Their wider argument was that strict dieting can set up a cycle of restraint and overeating. If that cycle has become a regular pattern for you, it’s worth raising with a doctor. You don’t need to be on a diet to recognize the smaller version, though. Skip the gym on Monday and it’s easy to decide the week is a write-off and start again next Monday.

Polivy, J. & Herman, C.P. (1985). “Dieting and binging: A causal analysis.” American Psychologist, 40(2), 193-201.

Research on smoking found that the explanation you give yourself after a slip matters too. In a 1987 study of smokers who had lapsed while trying to quit, Susan Curry, Alan Marlatt and Judith Gordon found that people who blamed the cigarette on something internal, stable and global, along the lines of “I have no willpower”, were more likely to relapse than people who put it down to the situation they were in. Researchers call this the abstinence violation effect.

Curry, S., Marlatt, G.A. & Gordon, J.R. (1987). “Abstinence violation effect: validation of an attributional construct with smoking cessation.” Journal of Consulting and Clinical Psychology, 55(2), 145-149.

When a Streak Works Against You

Apps add one more complication to the day after: they show you the broken streak. In a 2023 paper covering seven studies, Silverman and Barasch looked at how people react to streaks in records of their own behavior. People who saw an intact streak were more likely to do the activity again than people who saw a broken one, even when the total amount they had done was the same. A gap made people feel off track, and they did less.

How much less depended on how they saw the break. The drop was larger when people blamed themselves for it, and smaller when they had some way to repair the streak, which is roughly what the smoking research would predict.

Silverman, J. & Barasch, A. (2023). “On or Off Track: How (Broken) Streaks Affect Consumer Decisions.” Journal of Consumer Research, 49(6), 1095-1117.

Never Miss Twice

A rule of thumb follows from all this: you can miss once, but try not to miss twice in a row. No single study tested that rule, but it fits the findings above. One gap barely registers in a long run of repetitions. Two misses in a row start to look like a new routine, and that’s often the point where “I missed a day” turns into “I stopped”.

It helps to plan for the lapse before it happens. Decide now what the smallest acceptable version of the habit looks like on a bad day: five minutes of walking instead of thirty, one sentence instead of a page. Then, on the day after a miss, do that small version instead of trying to make up for lost time. Make-up sessions tend to be longer and harder than usual, which makes them easier to put off.

Keep the description of the miss specific, too. “I didn’t walk on Tuesday because the meeting ran late” is a fact about Tuesday. “I never stick to anything” is the internal, stable, global kind of explanation that the smoking study linked with relapse. And judge the month rather than the day. Twenty walks in thirty days is a lot of repetition, whatever the streak counter says this morning.

Lamplit keeps streaks and hands out badges, and they can help in the early weeks. If yours breaks, treat it as information rather than a verdict. The gap usually tells you something about which days are hardest to fit the habit into. On the day after a miss, keep the entry as small as you can. The mood check-in in the journal takes three taps and saves on its own. If you have another minute, write one short sentence for each of the three journal prompts, starting with “Today’s growth”.

Open the journal in Lamplit and log today’s mood. Three taps is enough to start again.