I’m sure most people have seen a typical google calendar embed, they look ugly at best and are impossible to read (on mobile), at worst. These shortcomings have led many developers to make alternative google calendar embeds, but they’re missing one key feature–the “Add to calendar” button.

Example Default Google Calendar Embed
Typical google calendar embed with add to calendar(+) buton in bottom right

The link this button navigates to can be generated fairly easily. After looking at the embed code, you can see that the URL follows the following format:

https://calendar.google.com/calendar/r?cid=ID

Where ID is the calendar identifier found in the google calendar’s settings page:

Google calendar id example
To find this page go to your google calendar's settings -> integrate calendar
Replace ID on the above URL with the calendar ID but REPLACE the @ with %40:

https://calendar.google.com/calendar/r?cid=c_5265c32323282w289sf299292%40group.calendar.google.com

Now this URL will redirect the user to add your calendar to their own google calendar.

References

Image credit: https://eventcalendarapp.com/blog/embed-google-calendar/