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Relative time (deprecated): relative_time

The relative_time template function returns a human-readable string describing how long ago a 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. occurred. Give it a datetime in the past, and it returns something like “2 hours” or “3 days”.

This function has been deprecated in favor of time_since, which provides the same functionality with the added ability to control precision. You should use time_since for all new templatesA template is an automation definition that can include variables for the action or data from the trigger values. This allows automations to generate dynamic actions. [Learn more]. relative_time remains available for backward compatibility, but may be removed in a future release.

Usage

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

As a function

As a filter

Template

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

Result (string)

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 = are usually required. A few optional parameters have no default value, so the signature shows them without a = as well. To check whether a parameter is required, look at the parameter list below the signature. Each parameter is marked as Required or Optional.

The most common optional parameter without a default value is default. The default parameter sets the value a function returns when the function can’t produce a result, for example, when float gets text that isn’t a number. If you leave out default, there is no fallback value, so most functions raise an error and the template fails. The parameter list of each function says what happens. If you set default, the function returns your value instead.

How to read a signature

Here is the signature of the round filter as an example:

round(
    value: Any,
    precision: int = 0,
    method: str = "common",
    default: Any,
) -> float | int | Any

round is the name of the function.
Between the parentheses are the parameters. Each parameter has a name, followed by a colon and the type of value the parameter expects. The type only tells you what kind of value to pass. For default: Any, you pass a value of any type, such as 0 or "unknown", not the word Any.
= 0 and = "common" are default values. You can leave out precision and method, and round uses these default values.
default has no =, but the parameter list marks default as optional. If you leave out default and round gets a value that isn’t a number, round raises an error.
-> shows the type of value the function returns.
Inside a signature, | means “or”. This function returns a decimal number, a whole number, or the value you passed as default.

round is a filter, so the first parameter, value, is the value before the |. For example, {{ 3.14159 | round(2) }} returns 3.14.

The types you’ll see most often:

str: text, such as "hello"
int: a whole number, such as 5
float: a decimal number, such as 3.14
bool: true or false
list: a list of values, such as [1, 2, 3]. list[str] is a list of texts.
dict: a set of keys and values, such as {"name": "Kitchen"}
datetime and timedelta: a date and time, and a duration. For details, refer to Dates and times.
None: no value
Any: any type of value

Some signatures use special forms:

*args means you can pass any number of values, separated by commas. For example, average(1, 2, 3).
value | name(...) means the function is a filter. The value before the | is passed to the filter as its first parameter. Some filter signatures, like the round example, show this value as the first parameter between the parentheses instead.

relative_time(
    value: datetime,
) -> str

Function parameters

The following parameters can be provided to this function.

value datetime Required

A datetime object representing a point in the past. The function calculates the time elapsed between this datetime and now.

Migrating to time_since

Replace relative_time with time_since in your templates. The basic usage is identical:

Template: Using time_since instead

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

Result (string)

2 hours

The advantage of time_since is the optional precision parameter, which lets you control how many time components to include in the output:

Template: time_since with precision

{{ time_since(states.binary_sensor.front_door.last_changed, 2) }}

Result (string)

2 hours 30 minutes

Good to know

Deprecated. Use time_since for new templates, which supports a precision argument.
Only returns the largest time unit, rounded to the nearest whole number. For example, 2 hours 15 minutes gives "2 hours", and 2 hours 45 minutes gives "3 hours".
Because of this rounding, the result doesn’t carry over to the next unit. For example, 59 minutes 40 seconds gives "60 minutes", not "1 hour".
A datetime in the future is returned unchanged, without an error.
If the input isn’t a datetime, it’s returned unchanged.
Datetimes without a time zone are accepted. They’re treated as your local time.

Try it yourself

Ready to test this? Open Settings > 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 ago something happened

Display the elapsed time since a sensor last changed stateThe state holds the information of interest of an entity, for example, if a light is on or off. Each entity has exactly one state and the state only holds one value at a time. However, entities can store attributes related to that state such as brightness, color, or a unit of measurement. [Learn more].

Template

{{
  "Last updated "
  ~ relative_time(states.sensor.temperature.last_changed) ~ " ago"
}}

Result (string)

Last updated 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.

Tip

AI assistants like ChatGPT or Claude can also explain or fix templates when you describe what you want in plain language.

Related template functions

These functions work well alongside this one:

Human-readable time elapsed: time_since - Returns a human-readable string describing how much time has passed since a datetime.
Human-readable time remaining: time_until - Returns a human-readable string describing how much time remains until a datetime.
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.

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