Daniel Mahaffy

The “All-in-One Event Calendar” by Time.ly works great, but uses dynamic javascript. 
This plugin creates a static version of the javascript that can be cached by 
the browser.
I have tested this plugin with versions 2.1.9 and 2.2.0 of the event calendar plugin. 
It may work with future releases, but use it at your own risk.
This plugin only uses the static javascript on the frontend. If a user is 
logged in, the original dynamic script will be used. As far as I can tell 
caching the javascript does not interfere with the plugin’s functionality, but 
there may be features of the event calendar that do not work with this plugin.

Fix Event Calendar Caching

This plugin makes the All-in-One Event Calendar's javascript cacheable to improve page load speed.

WordPress.org

Andrew Ozz

Marius L. J.

With the update to WordPress 5.5, a migration tool known as <code>jquery-migrate</code> was no longer enabled by default. This may lead to lacking functionality or unexpected behavior in some themes or plugins that run older code.
This plugin serves as a temporary solution, enabling the migration script for your site to give your plugin and theme authors some more time to update, and test, their code.
With the update to WordPress 5.6, the included version of jQuery is also upgraded. This means that old code that previously caused warnings now may instead may cause errors or stop working entirely.
Some of the features no longer working will just stop working behind the scenes without any apparent problem.
The plugin will let you downgrade to a previous version of jQuery for a period, but as a site administrator you are encouraged to get the underlying issue fixed.

Enable jQuery Migrate Helper

Also lets you know when it's no longer needed!!!!

This is what I call going above and beyond. I would rate 10 stars if I could. You deserve it.

Love it, super simple - perfect solution

Get information about calls to deprecated jQuery features in plugins or themes.

Fix Event Calendar Caching vs Enable jQuery Migrate Helper