About inmycalendar

inmycalendar is a daily Kanban board joined to a week-by-week calendar of the years around today. You plan one day in three columns, and above it you can see several years at once, laid out by week rather than by month. It is free, needs no sign-up, and keeps working with no internet connection.

The problem it solves

Most planning tools make you choose. A to-do app is good at today and blind to next March. A calendar app is good at next March and useless for ordering the six things you actually have to do before lunch. So people end up running both, and the two drift apart.

inmycalendar puts them on one screen. The board answers "what am I doing now". The year grid answers "when is that, and what else is near it". Marking a week of leave in June and seeing how it sits against a deadline in July takes one glance, not two apps.

Who it is for

• People who plan in weeks rather than in months, which is how most working life is actually scheduled
• Anyone tracking leave, travel, deadlines and days worked from home across a long horizon
• People who work across countries and need public holidays visible without looking them up
• Anyone who wants a planner that does not require an account before it will show them anything

What makes it different

A year read by week, not by month

Month grids break the year into twelve disconnected boxes, and a plan that spans the end of one month into the next becomes hard to see. Laying the year out as a continuous run of weeks keeps that span visible. Weeks that straddle a year boundary are shown greyed rather than dropped, so 31 December never quietly disappears.

Four things can be true about one day

A single day might be a public holiday, marked as leave, be today, and have three tasks on it. Those use four independent visual channels - a fill, a bottom stripe, a ring, and a corner dot - so they can all appear at once and stay readable. It is also why the app's own chrome is near-black: a coloured interface would compete with the colours that carry meaning.

Week numbers, in four different conventions

Everyone agrees a year has weeks. Nobody agrees which one is week 1, and most tools pick one answer quietly and hide the choice. This one offers four numbering rules across all seven week starts, which is twenty-eight combinations, so it can match ISO 8601, a US calendar, or whatever convention an employer's reporting weeks actually run on.

The distinction matters more than it sounds. ISO 8601 defines week 1 as the first week with four or more of its days in the new year, usually shortened to "the week containing the first Thursday". Those are the same sentence only when weeks begin on Monday, because Thursday is the fourth day of a Monday week. Start the week on Sunday and the fourth day is Wednesday, and the two phrasings give answers a full week apart. Both are in real use, so both are offered rather than one being applied silently under the other's name.

The rules are checked against independent arithmetic on every single day from 1995 to 2035, because a week number that is wrong at a year boundary is invisible: nothing breaks, nothing looks odd, and it surfaces months later as two reports that will not reconcile.

If you only need the number, what week is it answers that directly, and there are pages listing every week of 2026 and 2027 with their dates. The difference between ISO and US week numbers is explained in full there too.

Public holidays for 247 countries

Pick a country and its public holidays appear on the calendar. Only that one country's data is ever loaded, so the feature costs almost nothing to use. Regional holidays are an optional extra, because in some countries they outnumber the national ones several times over and bury them.

It works signed out, and offline

There is no sign-up wall. Open the site and start typing. Everything is stored in your own browser, and nothing is transmitted anywhere unless you decide to sign in. Signing in is optional and does one thing: it syncs your board between your devices. See the privacy page for exactly what is and is not collected in each case.

How it is built

Plain HTML, CSS and JavaScript. No framework, no build step, no bundler. That is a deliberate choice rather than a shortcut: it means the entire app can be opened, read and edited from any machine with a text editor, and it loads fast because there is very little to load.

It is covered by a large automated test suite that drives a real browser document with synthetic clicks and keystrokes, rather than checking that the source looks right. The source code is public on GitHub, including the reasoning behind every significant decision and a list of the bugs that cost the most time to find.

What it costs

Nothing. There is no paid tier today. Advertising is planned for a later version, and an ad-free option alongside it, at which point the privacy page will be updated before anything changes.