How to make a QR code for a calendar event

What the code holds

A calendar code holds an event in iCalendar format (RFC 5545), the same text that .ics files and calendar invitations use. An evening event with a place and a line of details looks like this:

BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//QR Island//EN
BEGIN:VEVENT
SUMMARY:Open studio evening
DTSTART:20261114T180000
DTEND:20261114T210000
LOCATION:Unit 4\, Mill Yard
DESCRIPTION:Drinks\, prints for sale and a short talk at 7 pm.
END:VEVENT
END:VCALENDAR

• SUMMARY is the title, LOCATION the place and DESCRIPTION the details.
• DTSTART and DTEND are the start and end: 14 November 2026 from 18:00 to 21:00.
• Commas and semicolons in the text get a backslash in front, and lines longer than 75 bytes are folded onto the next line.
• The VCALENDAR wrapper with VERSION and PRODID is what the standard asks for. Some generators write only the VEVENT part, which many Android scanners accept too.

Our codes leave out reminders, repeat rules, attendees and a unique ID. Calendar apps add their own ID on import, and a weekly class or a series of sessions is better served by a link to a page, as below.

iPhone and Android

• iPhone: the Camera app has recognised iCalendar event codes since iOS 11 and offers to add the event to Calendar.
• Android: Google Lens and the camera on many recent phones recognise the event and offer to add it to the calendar. Some scanner apps show the text instead, which isn’t a broken code, just a limited app.

Nothing is added until the person confirms, and they usually see the title, time and place first and can edit them. Of all the code types, events are the one where older phones and scanner apps are most likely to fall back to plain text, so test on more than one phone.

Time zones: floating local time

The times in QR Island’s event codes are floating local time: 20261114T180000, with no time zone and no Z for UTC. The phone adds the event at that clock time in whatever time zone it is set to.

• For events people attend in person, that is right. 6 pm on the poster is 6 pm in the calendar, whoever scans it.
• For people who travel to it, check. Some calendar apps keep floating times as they are; others fix them to the phone’s time zone when the event is added. An event scanned at home and attended in another time zone can then show the wrong hour once the phone changes zone. For a destination event, tell guests to check the time after they arrive, or use a link.
• For online events across time zones, it is wrong. A webinar at 15:00 in one city would land at 15:00 local time for everyone, wherever they are. Link to the event page instead, or send a calendar invitation by email, where the time zone travels with the event.

All-day and multi-day events

All-day events are written as dates, with no times:

DTSTART;VALUE=DATE:20261205
DTEND;VALUE=DATE:20261207

The end date is exclusive, so this is a two-day event on 5 and 6 December. It is a common source of off-by-one errors when people write the end date by hand; a generator should do it for you. In QR Island you tick All-day event and choose the first and last day, and the studio writes the end correctly. Left blank, the end is the same day.

For timed events, a blank end becomes one hour after the start. The end is always written, because some calendar apps treat an event without one as lasting no time at all.

All-day suits fairs, festivals, open weekends and deadlines. The event sits at the top of the day rather than at a time.

Density and print size

Everything in the event is in the pattern, so calendar codes are dense. The wrapper, the start and the end alone take about 150 characters before you add a title.

The sizes follow the rule our studio uses: at least 0.75 mm per module once a code is 57 modules wide or more, never under 2 cm. On a poster read from a metre away the code is 10 cm anyway, so density doesn’t matter. On a ticket, a postcard or a flyer it does: a 5.5 cm code plus its margin takes more than half the width of an A6 card. To make it smaller, shorten the details, drop the place if it is printed beside the code, or use a link.

When a link to an event page is better

A calendar code is right for a one-off event in one place, on a fixed date, for people who mostly want it in their calendar: a parents’ evening, an open day, a workshop on a noticeboard, a save-the-date. Our wedding guide weighs it up for invitations.

Link to an event page instead when:

• the details might change. A printed calendar code can’t be updated, and people who already added it keep the old time;
• the event is online, or people will join from several time zones;
• it repeats, or has several sessions to choose from;
• you need tickets, RSVPs or a map: the page can do all of that and offer its own “add to calendar” button;
• the code has to print small;
• you want the most dependable result: a plain link is the code type phones handle most reliably.

Make it in QR Island

In the studio, choose Event and fill in the title, the place, the start and end, the details, and whether it is all-day. The studio writes the full calendar format above, with floating local times, escaping and folding, and the size hint beside the message bar shows the smallest safe print width as you type.

Pick a world, such as Autumn Maple, and press Get QR code for the flat code to print, with PNG and SVG downloads and the free print sheet. Free codes are made in your browser and never expire. The island sign pack (+US$4.99, added to an Island pack) has an Event template: a PDF in each of its four styles with a poster, flyers, a table tent, cards and stickers, plus story, post and screen pictures.