Why habit tracking works
Habit tracking works through three mechanisms. First, it creates a visual record of behaviour that makes streaks viscerally motivating — the GitHub-style calendar showing 47 consecutive green days is a powerful incentive not to break the chain. Second, it shifts your identity: you are not "trying to exercise" but "a person who exercises," and the calendar is the evidence. Third, it introduces accountability to yourself — missing a day is visible and concrete rather than vague.
Research from Phillippa Lally at University College London found that habits take an average of 66 days to form, with a range of 18 to 254 days depending on the habit and person. The tracker's year-long calendar is designed for this timeline — it gives you enough runway to see real patterns and celebrate real milestones.
Setting up your habits
Add up to 10 habits using the input at the top. The best habits for tracking share three properties: they are binary (done or not done, not partially done), they can be completed in less than 5 minutes to assess, and they are within your direct control. "Exercise for 20 minutes" is trackable. "Feel motivated" is not. "Write 100 words" is trackable. "Write a great chapter" is not.
Start with 1–3 habits, not 10. The most common tracking mistake is adding every aspiration at once. Two habits tracked consistently for 90 days is more valuable than 10 habits tracked erratically for two weeks.
The year-view calendar
Click the calendar icon on any habit to see a GitHub-style contribution calendar showing the past 365 days. Green cells are completed days, grey cells are missed or unlogged days. Today's cell has a coloured outline. The calendar reveals patterns invisible in a streak count alone: do you consistently miss Sundays? Does your habit completion drop in certain months? These patterns tell you what environmental or scheduling changes to make.
Privacy and data storage
All data is stored in your browser's localStorage — nothing is ever sent to any server. This means your habit data is private but also tied to your browser. If you clear browser data, your history is lost. If you switch browsers or devices, your history does not follow. For long-term tracking across devices, consider exporting periodically (copy the localStorage data manually) or using a dedicated app once the habit is established.
The "don't break the chain" psychology
Jerry Seinfeld famously used this technique to write jokes every day — he put a red X on a wall calendar each day he wrote, and his only job was to not break the chain of X's. The visual momentum of a streak creates a psychological cost to missing a day that grows with the streak length. This is exactly what the tracker's streak counter and calendar exploit. Once you have a 30-day streak, missing day 31 feels genuinely bad — not because of external consequence but because of the visible break in the pattern.