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Parse a time string: strptime

The strptime template function parses a date/time string according to a format you specify and returns 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 a string like “15/03/2024 14:30” along with the matching format “%d/%m/%Y %H:%M”, and it converts the text into a proper datetime you can work with.

While as_datetime handles ISO 8601 formatted strings automatically, many sensorsSensors return information about a thing, for instance the level of water in a tank. [Learn more] and external data sources provide dates in non-standard formats. A weather service might return “March 15, 2024”, a calendar integration might give you “15/03/2024”, or a custom sensor might report “2024.03.15 14:30”. strptime lets you parse any date format by telling it exactly how the string is structured. The format codes follow Python’s strftime/strptime conventions.

Usage

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

As a function

{{ strptime("15/03/2024 14:30", "%d/%m/%Y %H:%M") }}

Result (datetime)

2024-03-15 14:30:00

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.

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.

strptime(
    string: str,
    fmt: str,
    default: Any,
) -> datetime | Any

Function parameters

The following parameters can be provided to this function.

string string Required

The date/time string to parse.

fmt string Required

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

default any (Optional)

The value to return if the text can’t be parsed with the given format, such as "unknown". If you leave out default and the text can’t be parsed, strptime raises an error and the template fails.

Common format codes

Here are the most frequently used format codes and what each one stands for:

%Y: four-digit year (for example, 2024)
%m: zero-padded month (for example, 03)
%d: zero-padded day (for example, 15)
%H: hour in 24-hour format (for example, 14)
%M: minute (for example, 30)
%S: second (for example, 00)
%B: full month name (for example, March)
%A: full weekday name (for example, Friday)
%I: hour in 12-hour format (for example, 02)
%p: AM or PM

Using a default value

If the string might not match the expected format, provide a default to avoid errors.

Template

{{ strptime("invalid", "%Y-%m-%d", default="unknown") }}

Result (string)

unknown

Good to know

The returned datetime has no time zone attached unless the format string includes one (for example, with %z). Compare it to another naive datetime or add a time zone before comparing with now.
Missing components default to their lowest value. A format that only parses a time gives you a datetime on 1900-01-01.
The format string must match the input exactly. Extra spaces, different separators, or a mismatched case for month names causes parsing to fail.

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.

Parse a date with month name

Parse a date string that uses the full month name.

Template

{{ strptime("March 15, 2024", "%B %d, %Y") }}

Result (datetime)

2024-03-15 00:00:00

Parse a 12-hour time format

Parse a time that uses AM/PM notation.

Template

{{ strptime("2:30 PM", "%I:%M %p") }}

Result (datetime)

1900-01-01 14:30:00

Parse and compare with now

Parse a date string from a sensor and check if it is in the past.

Template

{% set event_date = strptime(states("sensor.next_event"), "%Y-%m-%d %H:%M") %}
{{ event_date < now().replace(tzinfo=none) }}

Result (boolean)

false

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:

Convert to datetime: as_datetime - Converts a string or timestamp to a datetime object.
Convert to UNIX timestamp: as_timestamp - Converts a datetime object or string to a UNIX timestamp.
Current local date and time: now - Returns the current date and time in your local time zone.
Format timestamp with custom format: timestamp_custom - Formats a UNIX timestamp as a string using a custom format.

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