Blue hour ended

The Blue hour ended trigger fires when blue hour is over, the deep-blue twilight just before sunrise and just after sunset. Blue hour is the period when the sun’s elevation is between 6° and 4° below the horizon, just below golden hour. You can react to the end of the morning blue hour, the evening one, or both. Home Assistant calculates the exact time for every day from your home location.

Use it to switch to a full night setup once the evening sky is dark, or to wind down overnight lighting in the morning as the blue hour gives way to the golden light before sunrise.

Using this trigger from the user interface

If you prefer building automations visually, Home Assistant walks you through this trigger step by step. You pick what to watch, tweak a few options, and save. No YAML knowledge required.

To use this trigger in an automation:

1. Go to Settings > Automations & scenes.
2. Open an existing automation, or select Create automation > Create new automation.
3. In the When section, select Add trigger.
4. From the search box, search for and select Blue hour ended.
5. Under Period, select Any, Morning, or Evening.
6. Optionally, set an offset to fire before or after blue hour ends:
   • Under Offset, enter how far from the end of blue hour to fire, such as 10 minutes.
   • Under Offset type, select Before or After.
7. Select Save.

Options in the UI

Using this trigger in YAML

If you work directly in YAML, or you want to know exactly what Home Assistant does under the hood, this section has the technical reference. It lists the field names you use in YAML, their types, and which ones are required.

In YAML, refer to this trigger as sun.blue_hour_ended. A basic example looks like this:

trigger: sun.blue_hour_ended

This fires when either the morning or the evening blue hour ends. To react to only the morning or the evening, add the period option:

trigger: sun.blue_hour_ended
options:
  period: evening

To fire a fixed amount of time before or after blue hour ends, add the offset and offset_type options:

trigger: sun.blue_hour_ended
options:
  period: evening
  offset:
    minutes: 10
  offset_type: after

This fires 10 minutes after the evening blue hour ends.

Options in YAML

Good to know

• This trigger does not use a target. It applies to the sun at your configured home location.
• Blue hour is the period when the sun’s elevation is between -6° and -4°. In the morning, it ends as the sun rises past -4°, where golden hour begins. In the evening, it ends as the sun descends past -6°.
• To react to the moment blue hour starts, use Blue hour started. After the evening blue hour ends, the sky keeps darkening through the later twilight phases before it is fully dark. To check for those, use It is evening twilight or It is night as a condition.
• The length of blue hour changes through the year and with your latitude. Near the poles, it can last much longer or fail to occur on some days. When it does not occur, the trigger does not fire on that day.

Try it yourself

Ready to test this? Go to Settings > Automations & scenes, create a new automation, and add this trigger. Save the automation, then change the state of the targeted entity to watch the trigger fire on your actual entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more].

For this trigger, there is no target entity to change. To test it, wait for the next blue hour, or temporarily switch to a trigger you can control while you build the rest of the automation.

More examples

Real scenarios where this trigger fires in automations and scripts. Copy any example and adapt it to your setup.

Automation: close the blinds when evening blue hour ends

When the evening blue hour ends and the sky goes dark, close the living room blinds for the night.

• Trigger: Blue hour ended
  • Period: Evening
• Action: Close cover
  • Target: Living room blinds

alias: "Close blinds after evening blue hour"
triggers:
  - trigger: sun.blue_hour_ended
    options:
      period: evening
actions:
  - action: cover.close_cover
    target:
      entity_id: cover.living_room_blinds

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with the trigger you’re using and what you expected to happen, or share on our subreddit /r/homeassistant.

Related triggers

These triggers work well alongside this one:

• Blue hour started: Triggers when blue hour starts, in the morning, the evening, or either.

• Golden hour ended: Triggers when golden hour ends, in the morning, the evening, or either.

• Dusk: Triggers at dusk, when civil, nautical, or astronomical twilight ends.