The project is in a healthy, maintained state
Generate 'Add To Calendar' URLs for Android, Apple, Google, Office 365, Outlook, Outlook.com and Yahoo calendars


~> 2.0
~> 5.0
~> 0.13.1
~> 13.0.1
~> 0.9


>= 1.1, < 3
~> 1.2020
 Project Readme


A ruby gem to generate 'Add To Calendar' URLs for Android, Apple, Google, Office 365, Outlook, Outlook.com and Yahoo calendars.

If this gem brings you some value feel free to buy me a coffee :) ko-fi


Add this line to your application's Gemfile:

gem 'add_to_calendar'

And then execute:

$ bundle

Or install it yourself as:

$ gem install add_to_calendar


  • Ruby 2.0 or higher


# create new instance, adding your event attributes
@cal = AddToCalendar::URLs.new(
        start_datetime: Time.new(2020,12,12,13,30,00,0), 
        title: "Christmas party!", 
        timezone: 'Europe/London'

# access 'add to calendar' URLs
#=> "https://www.google.com/calendar/render?action=TEMPLATE&text=Christmas%20party%21&dates=20201212T133000/20201212T143000&ctz=Europe/London"

#=> "https://calendar.yahoo.com/?v=60&view=d&type=20&title=Christmas%20party%21&st=20201212T133000Z&dur=0100"

#=> "https://outlook.office.com/calendar/0/deeplink/compose?path=/calendar/action/compose&rru=addevent&subject=Christmas%20party%21&startdt=2020-12-12T13:30:00Z&enddt=2020-12-12T14:30:00Z"

# For outlook.com, different to Outlook the desktop application below
#=> "https://outlook.live.com/calendar/0/deeplink/compose?path=/calendar/action/compose&rru=addevent&subject=Christmas%20party%21&startdt=2020-12-12T13:30:00Z&enddt=2020-12-12T14:30:00Z"

# ical provides a data-uri which will download a properly formatted *.ics file (see 'Creating HTML links' section)
#=> "data:text/calendar;charset=utf8,BEGIN:VCALENDAR%0AVERSION:2.0%0ABEGIN:VEVENT%0ADTSTART:20201212T133000Z%0ADTEND:20201212T143000Z%0ASUMMARY:Christmas%20party%21%0AUID:-20201212T133000Z-Christmas%20party%21%0AEND:VEVENT%0AEND:VCALENDAR"

# android_url, apple_url and outlook_url are simply helper methods that call ical_url and return the same string.

Creating HTML links

<!-- Simply pass the url into the href Eg. in ERB -->
<a href="<%= @cal.google_url %>">Add to Google Calendar</a>

<a href="<%= @cal.yahoo_url %>">Add to Yahoo Calendar</a>

<!-- for ical_url, android_url, apple_url and outlook_url you can set the filename like so -->
<a download="calendar-event.ics" href="<%= @cal.ical_url %>">Download iCal</a>

Event attributes

event_attributes = {
    start_datetime: Time.new(2020,12,12,9,00,00,0), # required
    end_datetime: Time.new(2020,12,12,17,00,00,0),
    title: "Ruby Conference", # required
    timezone: 'America/New_York', # required
    location: "20 W 34th St, New York, NY 10001", 
    url: "https://www.ruby-lang.org/en/",
    description: "Join us to learn all about Ruby.",
    add_url_to_description: true, # defaults to true
    all_day: true # defaults to false

cal = AddToCalendar::URLs.new(**event_attributes)
Attribute Required? Class Notes
start_datetime Yes Time
end_datetime No Time
  • If not provided, defaults to start_datetime + 1 hour
  • Must be > start_datetime
title Yes String
timezone Yes String Must be in tz database format Eg. 'Europe/London', 'America/New_York'
location No String
url No String Most providers do not have a native URL field. If you set url it will be added to the end of the description field (see add_url_to_description)
description No String Accepts newlines by passing \n Eg. "Join us for fun & drinks\n\nPS. Smart casual"
add_url_to_description No true/false Defaults to true. Set add_url_to_description: false to stop the URL from being added to the description
all_day No true/false
  • Defaults to false.
  • When set to true the times will be ignored.
  • If no end_datetime provided it will be a single day event.
  • When providing end_datetime, use the final day of the event (eg. 1 day event start: 2023-05-01, end: 2023-05-01; 3 day event start: 2023-05-01, end: 2023-05-03).
  • Some calendars require you to specify the day after as the end date which feels counterintuitive, this Gem takes care of that for you.

Timezones and offsets

  • Offset values eg. "2020-05-13 15:31:00 +05:00" are ignored. It is only important that you have the correct date and time numbers set. The timezone is set directly using its own attribute timezone.
  • You must set a timezone so that when users add the event to their calendar it shows at their correct local time.
    • Eg. London event @ 2020-05-13 13:30:00 will save in a New Yorker's calendar as local time 2020-05-13 17:30:00

Browser support

  • IE11 and lower will not work for ical_url, apple_url and outlook_url (IE does not properly support data-uri links. See #16).
  • IE11 will also not work with Yahoo, but this is because Yahoo is deprecating IE 11 support and only offers a simplified interface which does not work with the add event URL.
  • Office 365 and Outlook.com do not work on mobile. This seems to be an issue on Microsoft's side. Their mobile web interface does not support the 'create event' URLs and the links do not open the apps if you have them installed.

More details

  • Read the Wiki for more specific details

Why build this?

I couldn't find an approriate gem or javascript library that did exactly what I wanted. So I decided to scratch my own itch to solve a problem for a startup I'm working on: https://www.littlefutures.org



After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.


Bug reports and pull requests are welcome on GitHub at https://github.com/jaredlt/add_to_calendar.


The gem is available as open source under the terms of the MIT License.