2026.10.4
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Format timestamp with custom format: timestamp_custom

The timestamp_custom filter formats a UNIX timestamp into a human-readable string using a format pattern you specify. Give it a timestamp and a format string like “%H:%M” or “%Y-%m-%d”, and it returns the formatted date and time.

This is useful whenever you have a UNIX timestamp (a number of seconds since January 1, 1970) and want to display it in a specific format. Many sensorsSensors return information about a thing, for instance the level of water in a tank. [Learn more] expose timestamps as attributes, and external APIs often return times as UNIX timestamps. With timestamp_custom, you can turn those numbers into readable dates and times in exactly the format you need. By default, the timestamp is converted to your local time zone, but you can set the second parameter to false to keep it in UTC.

Usage

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

The examples use a time zone of UTC+1.

As a filter 
{{ 1710510600 | timestamp_custom("%H:%M") }}
Result (stringA piece of text, like a name, message, or entity ID. In templates, wrap strings in quotes, like "living_room" or "lights are on".) 
14:50

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.
value | timestamp_custom(
    date_format: str = "%Y-%m-%d %H:%M:%S",
    local: bool = True,
    default: Any,
) -> str | Any

Function parameters

The following parameters can be provided to this filter.

date_format string (Optional, default: “%Y-%m-%d %H:%M:%S”)

The format string describing the desired output. Uses Python strftime format codes such as %Y (year), %m (month), %d (day), %H (hour), %M (minute), %S (second).

local boolean (Optional, default: true)

Whether to convert the timestamp to the local time zone before formatting. Set to false to format in UTC.

default any (Optional)

The value to return if the formatting fails, such as "unknown". If you leave out default and the formatting fails, timestamp_custom raises an error and the template fails.

Formatting in UTC

By default, timestamp_custom converts the timestamp to your local time zone. Pass false as the second argument to format in UTC instead.

TemplateA 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] 
{{ 1710510600 | timestamp_custom("%H:%M", false) }}
Result (stringA piece of text, like a name, message, or entity ID. In templates, wrap strings in quotes, like "living_room" or "lights are on".) 
13:50

Common format patterns

Here are some patterns that cover the formats you need most often:

  • %Y-%m-%d produces 2024-03-15
  • %H:%M produces 14:30
  • %H:%M:%S produces 14:30:00
  • %d/%m/%Y produces 15/03/2024
  • %A, %B %d produces Friday, March 15
  • %I:%M %p produces 02:30 PM

Good to know

  • The input must be a UNIX timestamp (a number of seconds). Pass a datetime object through as_timestamp first.
  • The timestamp is converted to your Home Assistant time zone by default. Pass false as the second argument to format in UTC instead.
  • The input must be a number, not text. A numeric string such as "1700000000" fails too. Convert states with float or int first.
  • Without a default, the filter raises an error if the input isn’t a number. Provide one to keep templates from breaking on unavailable sensors.

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.

Format last changed time

Convert an entity’s last changed time to a UNIX timestamp with as_timestamp and then format it.

TemplateA 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] 
{{
  as_timestamp(states.sensor.temperature.last_changed)
  | timestamp_custom("%H:%M")
}}
Result (stringA piece of text, like a name, message, or entity ID. In templates, wrap strings in quotes, like "living_room" or "lights are on".) 
14:30

Display a full date and time

Format a timestamp as a complete, human-readable date and time string.

TemplateA 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] 
{{ as_timestamp(now()) | timestamp_custom("%A, %B %d at %H:%M") }}
Result (stringA piece of text, like a name, message, or entity ID. In templates, wrap strings in quotes, like "living_room" or "lights are on".) 
Friday, March 15 at 14:30

Using a default value

If a sensor might provide an invalid timestamp, use a default to avoid errors. float(none) turns an invalid state into none, so the default is used.

TemplateA 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] 
{{
  states("sensor.last_event") | float(none)
  | timestamp_custom("%Y-%m-%d", default="unknown")
}}
Result (stringA piece of text, like a name, message, or entity ID. In templates, wrap strings in quotes, like "living_room" or "lights are on".) 
unknown

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: