When Your Mother-in-Law Comes to Visit: Calendar-Driven Guest Mode in Home Assistant

One of the most underrated integrations in Home Assistant is the humble calendar.

Most people use calendars for reminders, birthdays, or garbage collection schedules. Useful? Absolutely. Exciting? Not exactly.

But what if your calendar could automatically prepare your house for guests?

Imagine this:

It’s Friday afternoon. Your mother-in-law is arriving for the weekend. Instead of rushing through a checklist, Home Assistant has already done the work for you. The guest bedroom is warm, the bathroom floor heating is running, the outdoor lights stay on a little longer, and your “turn everything off when nobody is home” automation won’t accidentally leave your guests sitting in the dark.

All because of a calendar entry.

Let’s build a calendar-driven Guest Mode that automatically adapts your home when visitors arrive.

Why Use a Calendar?

Home Assistant offers many ways to trigger automations:

• Motion sensors
• Presence detection
• Buttons
• Voice commands
• Time schedules

A calendar is different because it provides context.

When you add an event called:

“Guests staying over”

from Friday evening until Sunday afternoon, you’re telling Home Assistant exactly what is happening and for how long.

This makes calendars perfect for temporary changes to your smart home.

Components Used

The setup is surprisingly simple.

Home Assistant

The automation platform that coordinates everything.

Google Calendar Integration

You can use any supported calendar integration, but Google Calendar is one of the easiest options.

Create a dedicated calendar called:

Guest Mode

This keeps guest-related events separate from your personal appointments.

Input Boolean Helper

Create a helper called:

input_boolean.guest_mode

Think of this as a virtual switch.

When guests are expected, the switch turns on.

When they leave, it turns off.

Other automations throughout your home can then check whether Guest Mode is active.

Existing Automations

The real power comes from integrating Guest Mode into automations you already use.

Examples:

• Heating automations
• Lighting automations
• Security automations
• Energy-saving automations

Real-World Example

Let’s say your normal home setup looks like this:

Guest Bedroom

Normally maintained at:

• 16°C during winter

When guests arrive:

• Increase to 21°C

Bathroom

Normally:

• Floor heating off

When guests arrive:

• Floor heating enabled
• Temperature set to 23°C

Lighting

Normally:

• Hallway lights turn off after 2 minutes

When guests arrive:

• Extend timeout to 10 minutes

Energy Saving

Normally:

• Turn off lights when everyone leaves

When guests arrive:

• Disable this automation

This prevents confused guests from suddenly experiencing what appears to be a haunted house.

Creating the Calendar

Create a dedicated calendar called:

Guest Mode

Whenever someone is visiting, simply create an event.

Examples:

• Guests
• Weekend Visit
• Family Stay
• Mother-in-Law Visit
• Christmas Guests

The event duration determines how long Guest Mode remains active.

No buttons.

No dashboards.

No remembering to activate anything.

Just add a calendar entry.

Creating the Helper

In Home Assistant:

Settings → Devices & Services → Helpers

Create an Input Boolean called:

Guest Mode

Entity:

input_boolean.guest_mode

This helper becomes the central status indicator for your entire home.

Automation Example

The following automation enables Guest Mode whenever the calendar event starts and disables it when the event ends.

alias: Guest Mode from Calendar
description: Enable Guest Mode based on calendar events

triggers:
  - trigger: calendar
    entity_id: calendar.guest_mode
    event: start

  - trigger: calendar
    entity_id: calendar.guest_mode
    event: end

actions:
  - choose:
      - conditions:
          - condition: template
            value_template: "{{ trigger.event == 'start' }}"
        sequence:
          - service: input_boolean.turn_on
            target:
              entity_id: input_boolean.guest_mode

      - conditions:
          - condition: template
            value_template: "{{ trigger.event == 'end' }}"
        sequence:
          - service: input_boolean.turn_off
            target:
              entity_id: input_boolean.guest_mode

mode: single

This automation acts as a bridge between your calendar and the rest of your smart home.

Using Guest Mode in Other Automations

Now that Guest Mode exists, it can influence almost everything.

Heating Example

When Guest Mode is active:

condition:
  - condition: state
    entity_id: input_boolean.guest_mode
    state: "on"

Then set the guest room temperature:

service: climate.set_temperature
target:
  entity_id: climate.guest_room
data:
  temperature: 21

Preventing Lights from Turning Off

Suppose you have an automation that switches off lights automatically.

Simply add:

condition:
  - condition: state
    entity_id: input_boolean.guest_mode
    state: "off"

Now the automation only runs when guests are not present.

Taking It Further

Once you’ve built the basic version, things get interesting.

Different Types of Guests

Use event titles for different behaviors.

Examples:

Weekend Guests

• Guest room heating
• Bathroom heating
• Outdoor lighting

Christmas Guests

• Holiday lighting
• Additional heating
• Guest dashboard

Party

• Disable bedtime automations
• Keep outdoor lights active
• Extend music playback schedules

Mother-in-Law Visit

• Every light in the house on.
• Every room at exactly 21°C.
• Lawn mowed automatically.
• Robot vacuum operating at maximum effort.

Okay, maybe not that last one.

Or maybe exactly that last one.

Energy Considerations

One concern is increased energy usage.

Guest Mode often means:

• More heating
• More lighting
• Longer appliance runtimes

However, because Guest Mode is tied to a calendar event, these changes only remain active for the required period.

This is far more efficient than permanently keeping guest areas heated.

For example:

A guest room maintained at 16°C and only increased to 21°C during visits may save significant energy over the course of a year.

The same principle applies to electric floor heating, which can consume several kWh per day when operating continuously.

By linking heating schedules to actual guest visits, you get comfort when needed without unnecessary energy consumption.

Why This Works So Well

Many smart home automations react to events after they happen.

Motion sensors react when somebody enters a room.

Presence detection reacts when somebody arrives home.

A calendar allows Home Assistant to prepare in advance.

Your house knows guests are coming before they arrive.

That small difference transforms a reactive smart home into a proactive one.

And that is where smart homes start feeling genuinely smart.

Conclusion

Calendar integrations are often overlooked because they seem simple.

Yet a dedicated Guest Mode calendar can become one of the most practical automations in your entire Home Assistant setup.

By combining:

• A calendar
• An Input Boolean helper
• A few existing automations

you can create a home that automatically adapts whenever visitors arrive.

Whether it’s friends staying for the weekend, family visiting during the holidays, or your mother-in-law arriving for her annual inspection of your housekeeping standards, Home Assistant will be ready.

And with any luck, so will you.