To build the best
calendar tools in the world.

Thank you, community!

Anytime someone presses an "Add to Calendar" button there's a good chance AddEvent has something to do with it. We're proud to be the leading "Add to Calendar" service in the world.

A brief history of our company

  • Around the summer of 2012, Michael Nilsson was visiting friends in Palo Alto. While building a website for a client, Michael needed an “Add to Calendar” button. After a thorough search, he noted that no good solutions were to be found. Inside his classic Californian highway motel, Michael began writing the first lines of code for what would turn out to become the leading “Add to Calendar” service in the world.
  • Michael returned to Copenhagen, published a beta version of the button and incorporated AddThisEvent.com. In order to use the button, we asked the users to pay a license fee to support the development. The button was noticed in the development community and quickly became popular.
  • Understanding time zones and daylight savings time across the world can be a real head spinner, and that it was for us too. In early 2013, the button had been tested across the world and was taken out of beta mode.
  • In 2014 the “Event Manager” was introduced. The “Event Manager” made it possible to add an “Add to Calendar” link in newsletters and share events on social media like Facebook and Twitter.

    The service was growing rapidly and that was noticed by the current webhost. All additional services besides hosting were shut down due to massive traffic and pressure on the servers. In 2015 the code base was completely re-written and moved to the Amazon cloud.
  • On a visit in the Bay Area, Michael was introduced to Founder Partners, a constellation of company-builders. A strong bond was established and the company moved to San Mateo. At the same time, AddThis.com’s legal department reached out and wanted AddThisEvent to change to a different name. We agreed, and AddEvent.com was born and incorporated in California.
  • Launch of CalendarX.com
    In 2015, a simple “Subscription Calendar” button was introduced on AddEvent.com. The service was a request by many users, and with a lot of different purposes in mind. In late 2016 we expanded the functionality with lots of new features and launched CalendarX.com. CalendarX.com is a subscription calendar and an embeddable calendar for websites.
  • Launch of TimezoneAPI.io
    With AddEvent.com we had spent great amount of hours (days/months/years!!) understanding time zones and how they work. In early 2017 we launched TimezoneAPI.io. TimezoneAPI.io is an API which makes developers able to ping the service and it'll return time zone information based on IP addresses or physical addresses.

We are making sure your events
reaches your user's calendar.


unique newsletter events


calendar syns /day


calendar downloads /month


live scripts requests /day

We're handling an average of +30
calendar transactions every second.

Some of our incredible customers

If you need us...

We are located in San Mateo, California. A home to many data-driven
startups, conveniently located between San Francisco and Palo Alto.
If you are visiting the Bay Area, feel free to stop by.

Office address
AddEvent, Inc
400 Concar Dr
San Mateo, California, 94402