Create a time duration: timedelta

The timedelta template function creates a timedelta object from numeric values like days, hours, minutes, and seconds. This gives you a duration that you can add to or subtract from 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. objects to calculate future or past times.

Whenever you need to offset a time by a specific amount, timedelta is how you express that amount. For example, you might want to check if a sensor changed in the last 10 minutes, calculate what time it will be in 2 hours, or determine if an event happened more than 3 days ago. You create a timedelta with the desired duration and then add or subtract it from a datetime like now. If you need to parse a duration from an ISO 8601 string instead of numeric values, use as_timedelta.

Usage

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

{{ timedelta(hours=2, minutes=30) }}

2:30:00

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 = 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.

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

timedelta(
    days: float = 0,
    seconds: float = 0,
    microseconds: float = 0,
    milliseconds: float = 0,
    minutes: float = 0,
    hours: float = 0,
    weeks: float = 0,
) -> timedelta

Function parameters

The following parameters can be provided to this function. All parameters are optional and default to 0. You can combine multiple parameters to create any duration.

Good to know

• All arguments are keyword-only. Call it as timedelta(hours=2), not timedelta(2).
• Values can be negative and can exceed their usual range. timedelta(hours=36) and timedelta(days=1, hours=12) produce the same duration.
• There is no months or years argument. Use days=30 for an approximate month, or calculate a future date by adjusting now() components directly.

Adding and subtracting durations

The most common use is adding or subtracting a timedelta from now to calculate a time in the past or future.

{{ now() - timedelta(hours=1) }}

2024-03-15 13:30:00.123456+01:00

{{ now() + timedelta(days=7) }}

2024-03-22 14:30:00.123456+01:00

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.

Check if something changed recently

Determine whether a sensor 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] in the last 10 minutes.

{{
  now() - states.binary_sensor.motion.last_changed
  < timedelta(minutes=10)
}}

true

Check if something is overdue

Determine whether a plant was last watered more than 3 days ago.

{{
  now() - states.sensor.plant_last_watered.last_changed
  > timedelta(days=3)
}}

false

Calculate a future time for display

Show what time it will be in 45 minutes, formatted for a notification.

{{ (now() + timedelta(minutes=45)).strftime("%H:%M") }}

15:15

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:

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

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

• Current UTC date and time: utcnow - Returns the current date and time in UTC.

• Today at a specific time: today_at - Returns today’s date combined with a specific time.

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