Set date/time value

Use this action to set a date/time entity to a specific date and time, for example a next-departure moment, a reminder, or any other timestamp you keep track of in Home Assistant.

Using this action from the user interface

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

To set a date and time from an automation or a script:

1. Go to Settings > Automations & scenes.
2. Open an existing automation or script, or select Create automation > Create new automation.
3. If you’re setting up a new automation, add a trigger in the When section. Scripts don’t need a trigger. They run when something else calls them.
4. In the Then do section, select Add action.
5. Select what you want to control. Under By target (see Targets), select the date/time entity you want to set.
6. From the actions shown for that target, select Set date/time.
7. Set the Date & Time you want to apply.
8. Select Save.

Options in the UI

Using this action 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 action as datetime.set_value. A basic example looks like this:

action: datetime.set_value
target:
  entity_id: datetime.next_departure
data:
  datetime: "2024-11-01T07:15:00"

This sets datetime.next_departure to November 1, 2024 at 07:15.

Options in YAML

Targets of the action

This action requires a target. The target is the object of the action. You can point the action at a single entityAn 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], a device, an area, a floor, or a label, and Home Assistant will run the action on every matching datetime entity behind that target.

• Entity: one specific datetime entity, such as datetime.living_room.
• Device: every datetime entity that belongs to a device.
• Area: every datetime entity in a room or area.
• Floor: every datetime entity on a floor.
• Label: every datetime entity that shares a label.

You can also select different target types in one action. For example, you can add a specific entity and an area as targets in the same action to run the action on both of them at once.

Good to know

• This action only works with date/time entities.
• If you leave out the time zone, Home Assistant uses its own configured time zone.

Try it yourself

Ready to test this? Open Developer tools > Actions, search for this action, fill in the fields, and select Perform action. You see what happens 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] without writing a line of YAML.

More examples

Real scenarios where this action shows up in automations and scripts. Copy any example and adapt it to your setup.

Automation: set a departure time when you leave for work

Update a date/time entity to a fixed moment, for example to record the next planned departure.

• Trigger: State: Work mode turns on
• Action: Set date/time
  • Target: Next departure
  • Date & time: A moment of your choosing

- alias: "Set the next departure time"
  triggers:
    - trigger: state
      entity_id: input_boolean.work_mode
      to: "on"
  actions:
    - action: datetime.set_value
      target:
        entity_id: datetime.next_departure
      data:
        datetime: "2024-11-01T07:15:00"

Still stuck?

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