Convert to UNIX timestamp: as_timestamp

The as_timestamp template function converts 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. object or a date/time string into a UNIX timestamp. The result is a floating-point number representing the number of seconds since January 1, 1970 (the UNIX epoch).

UNIX timestamps are useful when you need to perform arithmetic with dates and times, since they are plain numbers that can be added, subtracted, and compared. For example, you can subtract two timestamps to find the number of seconds between two events, or add a number of seconds to find a future time. Many external services and APIs also expect timestamps in this format. You can convert the result back to a readable date using timestamp_custom, timestamp_local, or as_datetime.

Usage

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

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("2024-03-15T14:30:00+01:00") }}
Result (floatA number that can have decimal places, like 21.5 or 3.14. Used for temperatures, percentages, and other measurements that need precision.)
1710510600.0

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.

as_timestamp(
    value: datetime | str,
    default: Any = None,
) -> float | Any

Function parameters

The following parameters can be provided to this function.

value string | datetime Required

The datetime object or date/time string to convert. Strings must be in a recognized date/time format (for example, ISO 8601).

default any (Optional)

Value to return if the conversion fails. If not provided, an error is raised on invalid input.

Converting the current time

You can convert now or utcnow to get the current UNIX timestamp.

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()) }}
Result (floatA number that can have decimal places, like 21.5 or 3.14. Used for temperatures, percentages, and other measurements that need precision.)
1710510600.0

Using a default value

If the input might be invalid, provide a default to avoid errors.

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("not a date", default=0) }}
Result (floatA number that can have decimal places, like 21.5 or 3.14. Used for temperatures, percentages, and other measurements that need precision.)
0

Good to know

  • The result is a UNIX timestamp in seconds (a float), not milliseconds.
  • Without a default, unparseable strings raise an error.
  • Subtracting two timestamps gives a duration in seconds, which can be compared directly with numeric thresholds.

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.

Seconds since an entity last changed

Calculate how many seconds have passed 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].

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())
   - as_timestamp(states.binary_sensor.front_door.last_changed))
  | int
}}
Result (integerA whole number without decimal places, like 1, 42, or -5. Used for counts, indices, and whole values.)
3847

Check if something happened in the last 5 minutes

Determine whether the front door opened in the last 300 seconds.

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())
   - as_timestamp(states.binary_sensor.front_door.last_changed))
  < 300
}}
Result (booleanA value that is either true or false. Used for on/off states, yes/no conditions, and similar binary choices.)
true

Format a timestamp for display

Convert a datetime string to a UNIX timestamp and then format it using timestamp_custom.

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("2024-03-15T14:30:00+01:00")
  | 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

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: