Updated versions of My Calendar are shipped fairly regularly. Minor updates are any change in the 3rd digit (e.g. updating from 3.5.6 to 3.5.7). In a minor update, very little will change; almost always only bug fixes. This doesn’t mean that nothing can go wrong, but generally the changes are slight.

Major updates contain more significant changes. These changes may impact the front-end of your site.

There is no significant difference between a second digit change (3.4 to 3.5) and a first digit change (3.9 to 4.0).

Upgrade Path Policies

My Calendar has upgrade processes that run whenever you do an update that requires significant changes. These updates may migrate options to a different format, add default values for new options, or modify the database.

Upgrade paths are not maintained indefinitely. Any given upgrade path will be kept in place for approximately five years.

Right now (August 30th, 2025), the oldest version with a full upgrade path is version 3.1.13, released in August 2019. This will be removed when version 3.7 is released.

Accessibility-first Development

Since version 3.5, My Calendar is developed with an accessibility-first mindset. This means that if I need to make a breaking change for accessibility reasons, I will do this. Breaking changes will still only occur in major releases, and will never occur in a 3rd-digit release.

Most accessibility changes will be modifications to the My Calendar HTML output, and the primary change that will occur on your site is that custom styles may break.

I updated, and everything looks wrong!

Most likely, this is a caching issue. While something could go wrong in an update, the most common problem is that you have updated HTML or settings, but out of date CSS or JavaScript.

If you have any caching plugins in your environment, clear those caches, then go and view your site in a private tab in your browser. This helps ensure that you’re not seeing it with either a cache from the site or a cache from your browser.