Dates, durations & the now keyword

CalNote can now calculate with calendar dates. A new now keyword gives you the current moment, date literals let you anchor specific days, and the existing time units (day, week, hour, min) flow straight into date arithmetic. If you know how to type 1 km + 500 m, you already know how to count down to a deadline.

The now keyword

now resolves to the current date and time every time a line is evaluated. Add or subtract a duration and you get a new date:

Notice the display switches between date and date & time based on the unit you add. Day-level arithmetic (day, week, month, year) collapses to a plain calendar date. Sub-day units (h, min, s) keep the time-of-day. The last operation wins — so now + 2 days + 1 h shows the full datetime, and now + 1 h + 2 days collapses to a date.

Static date literals

Need to reference a specific day? Type it inline. ISO form is always safe:

The T HH:MM suffix is optional — include it to anchor a specific time of day.

Slash forms work too, and they follow the Date format setting in the Settings modal. If you’ve selected US (MM/DD/YYYY), writing 05/02/2026 means May 2nd. If you’ve selected EU (DD/MM/YYYY), 02/05/2026 also means May 2nd. ISO input (2026-05-02) works under any setting.

The same setting controls how results are rendered in the results column — pick ISO, US, or EU and every date on every board updates instantly.

One footgun to know: the parser only treats a date literal as a date when there’s no whitespace around the separators. 2026-05-02 is a date; 2026 - 05 - 02 is arithmetic (and evaluates to 2019).

Subtract two dates to get a duration

Any two dates can be subtracted. The result is a duration in day, which converts to any other time unit via to:

Practical use cases

Every example below is live — type over it to experiment. Edits reset when you refresh.

1. The freelance invoice

Weekday hours at a fixed rate, plus tax. The billing period is bounded by two dates, so changing either end rebalances the invoice instantly:

2. Countdown to an event

Flights, launches, weddings — anything on the calendar. Use T HH:MM for the exact moment, then read the gap in whatever unit is most useful:

3. How old am I — in any unit

Subtract a birthday from now and you’ve got a duration. to can translate it into years, hours, or all the way down to milliseconds — and because the result depends on now, the seconds column keeps ticking in real time:

4. Prorated rent after a mid-month move-in

Landlord wants a partial month? Days occupied divided by days in the month, times full rent. No calendar math in your head:

How it fits with the rest of CalNote

• Variables carry dates across lines. deadline = now + 5 days stores a date; reference deadline anywhere below.
• Errors are explicit. Invalid literals like 2026-02-30, nonsense like now * 2, or duration - date show the familiar ø error indicator.
• Shared boards respect your setting. Export a board as a link or an <script> embed and the date format travels with it — or let visitors toggle ISO / US / EU right in the embed header.

Dates are the last “thing you can type” that a notepad calculator was missing. Open app.calnote.eu and try now + 2 days.