Human-readable time elapsed: time_since

The time_since template function returns a human-readable string describing how much time has elapsed since a given datetimeA value representing a specific moment in time, including the date, time, and time zone. For example, 2026-04-05 14:30:00+00:00. Used for timestamps, scheduling, and time-based calculations.. Give it a datetime in the past, and it returns something like “2 hours” or “3 days and 5 hours” instead of a raw number of seconds.

This is useful whenever you want to display elapsed time in a natural, readable format. For example, showing “last seen 45 minutes ago” on a dashboard, displaying how long a door has been open, or reporting how long ago a sensor last updated. The function only works with datetimes in the past. For future datetimes, use time_until instead. You can control the level of detail with the optional precision parameter, which determines how many time components (years, months, days, hours, minutes, seconds) to include.

Usage

Here’s how to use this template function. Copy any example and adjust it to your setup.

{{ time_since(states.binary_sensor.front_door.last_changed) }}

2 hours

{{ states.binary_sensor.front_door.last_changed | time_since }}

2 hours

Function signature

The signature is a technical summary of this template function. It shows the name of the function, the values (called parameters) it accepts, and what type of data each parameter expects (for example, a piece of text or a number).

Function parameters that have a = with a value after them are optional. If you leave them out, the default value shown is used automatically. Function parameters without a default are required.

time_since(
    value: datetime,
    precision: int = 1,
) -> str

Function parameters

The following parameters can be provided to this function.

Controlling precision

By default, time_since returns only the largest time component. Increase the precision to include more detail.

{{ time_since(states.binary_sensor.front_door.last_changed, 1) }}

2 hours

{{ time_since(states.binary_sensor.front_door.last_changed, 3) }}

2 hours, 30 minutes and 15 seconds

Good to know

• Only works with datetimes in the past. For future datetimes, use time_until instead.
• Durations shorter than one second return "0 seconds".
• The input datetime must be time zone aware. Pass something like states.sensor.foo.last_changed or now(), not a naive datetime.

Try it yourself

Ready to test this? Open Developer tools > Template, paste the example into the Template editor, and watch the result update on the right. Edit the values to see how the function adapts to your own 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].

More examples

Real scenarios where this function comes up in automations and templates. Copy any example and adapt it to your setup.

Show how long a door has been open

Display the elapsed time since a door opened on your dashboard.

{{
  "Open for "
  ~ time_since(states.binary_sensor.front_door.last_changed)
}}

Open for 2 hours

Detailed elapsed time in a notification

Send a notificationYou can use notifications to send messages, pictures, and more, to devices. [Learn more] with a more detailed breakdown of elapsed time.

action:
  - action: notify.mobile
    data:
      message: >
        The washing machine has been running for
        {{ time_since(states.sensor.washer_start.last_changed, 2) }}.

Show when something was last seen

Create a “last seen” display for a person tracker.

{{
  "Last seen "
  ~ time_since(states.person.paulus.last_changed) ~ " ago"
}}

Last seen 45 minutes ago

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with your template and expected result, or share on our subreddit /r/homeassistant.

Related template functions

These functions work well alongside this one:

• Human-readable time remaining: time_until - Returns a human-readable string describing how much time remains until a datetime.

• Relative time (deprecated): relative_time - Returns a human-readable string describing how long ago a datetime was.

• Current local date and time: now - Returns the current date and time in your local time zone.

• Convert to datetime: as_datetime - Converts a string or timestamp to a datetime object.

• Convert to UNIX timestamp: as_timestamp - Converts a datetime object or string to a UNIX timestamp.