I have a cloud-synced calendar on my phone and computer, which I use to track work, plans, and reminders. I figured Home Assistant’s built-in calendar was surplus to my requirements.

It turns out that I’ve been missing out, and maybe you have too.

How I use Home Assistant’s calendar

I’ve started using Home Assistant’s calendar to track home-specific events, with the main catalyst being recycling collection. This happens once every two weeks, and missing it can result in a miserably full bin. I’ve been hunting for some sort of visual indicator to remind me, with inspiration coming from a Home Assistant project called the Bindicator.

So I created a new calendar in Home Assistant and made a weekly event called “Recycling” with a bi-weekly interval. Now I have access to a trigger that I can use in automations so that I’ll never be up to my ears in cardboard and cans again. I made the event window three hours long, right around the time I get home from the gym, to give me plenty of time to work with.

I’ll get to precisely how I’m using this trigger shortly, but it’s worth thinking about other ways you could use a calendar for home and smart-home specific events. For example, we could all use a reminder to change the batteries in our water leak sensors and smoke alarms every 12 months.

Home Assistant never updates itself by design, so it can be easy to fall behind and miss out on features and fixes. Setting a monthly event in the third week of every month (so that the bugs from the newest release have been ironed out) might be the catalyst you need to stay on top of this.

You can even get really wild and trigger a restart sequence that happens once every few months, in the middle of the night, if you find that your Home Assistant server struggles without doing so.

Use calendar events to trigger automations

The way that Home Assistant handles calendar event triggers is interesting. There are two triggers you can use in your automations: when any event in a specified calendar starts, and when any event in a specified calendar ends. Note that I said “any event” and not specific events.

You’ll find these under “Calendar” when you click “Add trigger,” with “Calendar event started” being the obvious choice for most cases.

You can’t designate a specific event (like “Recycling” in my example) in the trigger field, but you can add a condition in the “And if” section of the automation to use specific events. To do this, click “Add condition” and choose “Template,” then use the following line:

{{ 'Event' in trigger.calendar_event.summary }}

Replace Event with the exact event name (in my case, that’s Recycling so that the line looks like:

{{ 'Recycling' in trigger.calendar_event.summary }}

Finally, you can specify the action that you want to happen in the “Then do” actions field. This can be anything you want, from playing a sound effect on a smart speaker to turning an automation on, running a script, triggering a robot vacuum cleaner—whatever you want.

If you want to reverse an action when the event ends, you can create a second automation using the “Calendar event ended” trigger.

Using calendar event triggers with my signal light

I recently discovered a Home Assistant integration called Signal Light. A signal light is essentially a colored light that remains on for as long as an event lasts (or for a designated period of time). By designating a simple colored bulb as a signal light, you can do things like turn the light on whenever your garage door is open, or fire off a color signal when someone arrives home.

I’m using this integration with calendar events so that I can use my signal light as a universal indicator. To do this, I created a custom signal within the integration for the recycling alert, and then I used the Signal Lights > Trigger Signal action to call on it in my automation.

Since the signal remains on forever once triggered, I also added an automation that dismisses the signal using the “Calendar event ends” trigger.

Are there easier ways to do this? Perhaps. Was I pleased when I finally got the recipe right? Absolutely. I won’t pretend to be a YAML expert, and I’m a firm believer that “if it ain’t broke, don’t fix it.”

• 

  Dimensions (exterior)

  4.41″L x 4.41″W x 1.26″H

  Weight

  12 Ounces

  Home Assistant Green is a pre-built hub directly from the Home Assistant team. It’s a plug-and-play solution that comes with everything you need to set up Home Assistant in your home without needing to install the software yourself. 

  
  

• 

  Brand

  Cync

  Integrations

  Matter, Alexa, Apple Home, Google Home, Samasung SmartThings

  The Cync Clear Full Color Direct Connect A19 Smart Bulb is a clear version of Cync’s existing full-color smart bulb, making it look much more like a traditional incandescent bulb. Able to be set up via Matter without using a specific companion app, Cync’s bulb is compatible with virtually all smart home ecosystems.

  
  

However you use them, calendar events can give your Home Assistant server useful additional triggers—especially when combined with repeating events.

You can also add your Google Calendar, iCloud calendar using CalDAV, and Outlook calendar with Remote Calendar to use these events as triggers too.