Convert to datetime: as_datetime

The as_datetime template function converts a date/time string or a UNIX timestamp into 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. Give it an ISO 8601 formatted string like “2024-03-15T14:30:00” or a numeric timestamp, and it returns a proper datetime you can work with in your templates.

Many sensorsSensors return information about a thing, for instance the level of water in a tank. [Learn more] and integrationsIntegrations connect and integrate Home Assistant with your devices, services, and more. [Learn more] provide dates and times as plain text strings or UNIX timestamps. To compare those values with now, calculate time differences, or format them for display, you first need to turn them into datetime objects. as_datetime handles this conversion for you. It accepts ISO 8601 formatted strings (the most common format in Home Assistant) as well as numeric UNIX timestamps.

Usage

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

{{ as_datetime("2024-03-15T14:30:00+01:00") }}

2024-03-15 14:30:00+01:00

{{ "2024-03-15T14:30:00+01:00" | as_datetime }}

2024-03-15 14:30:00+01:00

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

Function parameters

The following parameters can be provided to this function.

Converting from a UNIX timestamp

You can also convert a numeric UNIX timestamp (seconds since January 1, 1970) into a datetime object.

{{ as_datetime(1710510600) }}

2024-03-15 14:30:00+00:00

Using a default value

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

{{ as_datetime("not a date", default="unknown") }}

unknown

Good to know

• Strings without a time zone are treated as local time; strings with an offset or Z suffix keep the original zone.
• UNIX timestamps are interpreted in UTC, so chain with as_local if you need local time.
• Without a default, an unparseable input raises an error.

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.

Convert a sensor value to a datetime

Many sensors store dates as strings. Convert them to datetime objects to perform comparisons or calculations.

{{ as_datetime(states("sensor.next_appointment")) }}

2024-03-15 14:30:00+01:00

Calculate time until a future event

Convert a date string from a sensor and calculate how many hours remain until that event.

{% set event = as_datetime(states("sensor.next_appointment")) %}
{{ ((event - now()).total_seconds() / 3600) | round(1) }}

3.5

Chain with as_local

Convert a UTC datetime string to your local time zone by chaining as_datetime with as_local.

{{ as_datetime("2024-03-15T13:30:00+00:00") | as_local }}

2024-03-15 14:30:00+01:00

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:

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

• Convert to local time zone: as_local - Converts a datetime object to your local time zone.

• Parse duration string: as_timedelta - Parses an ISO 8601 duration string into a timedelta object.

• Parse a time string: strptime - Parses a time string with a specified format into a datetime object.

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