For all those who don't know where to store their calendars safely, a good option may be Radicale, What is a CalDAV and CardDAV server, Free and open source, that will allow our computers or mobile devices to synchronize calendars in a centralized way!

If you want to manage your own calendars, Avoiding paid cloud services (or 'free') we can mount locally in a Docker container, a calendar manager. Radicale is very, very simple, It will allow us to register and once inside we will be able to create as many calendars as we need, or for contacts go. Later we can connect any calendar client to Radicale and thus keep it synchronized with the rest of the devices.

I leave you his Official website where you can find any detail, and the GitHub to deploy it in Docker in case you need it. So yes, we're going to deploy Radicale in a minute thanks to a Docker container! With Docker already installed, we simply run:

docker run -d --name radicale \
    -p 5232:5232 \
    --Init \
    --read-only \
    --security-opt="no-new-privileges:True" \
    --cap-drop ALL \
    --cap-add CHOWN \
    --cap-add SETUID \
    --cap-add SETGID \
    --cap-add KILL \
    --pids-limit 50 \
    --memory 256M \
    --health-cmd="curl --fail http://localhost:5232 || exit 1" \
    --health-interval=30s \
    --health-retries=3 \
    -v /mnt/data-radicale:/date \
    tomsquest/docker-radicale

We access Radicale with a browser, to the port 5232 Default, Something like HTTP://DIRECCION_IP_DOCKER:5232 will give us access. The username and password we provide will be our first user,

We will not have calendars, so we can directly create an agenda or a calendar, as is the case. Click on 'Create new addressbook or calendar',

We give you a name, a description and the type of items we want to store, Tasks, calendar, Contacts… as well as a color for this calendar.

We can create as many as we need, it will show us the URL we will need when we want to connect any calendar through CalDAV.

For example, if you use Outlook that does not use CalDAV, Well, you can put a plugin called ‘CalDAV Synchronizer‘ where we can easily add our calendars and keep them updated at all times with the rest of the devices.

On our mobile, if we use Android, we can download an app to synchronize them and be able to view them in the native calendar, for this, DAVx⁵ can come in handy, a CalDAV customer, CardDAV and WebDAV quite interesting.

And nothing, That's how simple we can set up our own calendar or contact server; local, sure, open source… Send you a big hug, And as my grandmother would say, See you in a few days, God willing!