# Datetimes

SurrealDB has native support for datetimes with nanosecond precision. SurrealDB is able to parse datetimes from strings.

SurrealDB has native support for datetimes with nanosecond precision. SurrealDB automatically parses and understands datetimes which are written as strings in the SurrealQL language. Times must also be formatted in [RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339) format.

Datetimes are represented by and can be created using a `d` prefix in front of a string.

```surql
CREATE event SET time = d"2025-07-03T07:18:52Z";
```

SurrealDB handles all datetimes with nanosecond precision.

```surql
CREATE event SET time = d"2025-07-03T07:18:52.841147Z";
```

A datetime can be created with a timezone, which will be converted and stored as a UTC date.

```surql
d"2025-07-03T07:18:52.841147+02:00";

-- Output:
d'2025-07-03T05:18:52.841147Z';
```

A `datetime` can also be created by using `<datetime>` to cast from a string.

With correct input:

```surql
CREATE event SET time = <datetime>"2025-07-03T07:18:52.841147Z";
```

```surql title="Response"
[
    { 
        id: event:jwm8ncmfi30nrxdf24ws, 
        time: d'2025-07-03T07:18:52.841147Z' 
    }
]
```

With incorrect input (missing final Z):

```surql
CREATE event SET time = <datetime>"2025-07-03T07:18:52.841147";
```

```surql title="Response"
"Expected a datetime but cannot convert '2025-07-03T07:18:52.841147' into a datetime"
```

As a convenience, a date containing a year, month and day but no time will also parse correctly as a datetime.

```surql
CREATE event SET time = <datetime>"2024-04-03";
```

```surql title="Response"
[
    { 
        id: event:4t50wjjlne9v8km2qcwq, 
        time: d'2024-04-03T00:00:00Z' 
    }
]
```

## Datetime types in `DEFINE FIELD` statements

Defining a field with a set `datetime` type will ensure that datetimes are properly formatted and not passed on as simple strings.

```surql
DEFINE FIELD time ON event TYPE datetime;
// highlight-next-line
CREATE event SET time = "2025-07-03T07:18:52.841147";
```

```surql title="Response"
"Couldn't coerce value for field `time` of `event:qv8qcjf0w9oowekl36w6`:
Expected `datetime` but found `'2025-07-03T07:18:52.841147'`"
```

The above query will fail because the datetime is not cast as a datetime type. The correct input is:

```surql
DEFINE FIELD time ON event TYPE datetime;
// highlight-next-line
CREATE event SET time = d"2025-07-03T07:18:52.84114Z";
```

```surql title="Response"
[
    { 
        id: event:w2lhv58f7c9z7xo4nqkq, 
        time: d'2025-07-03T07:18:52.841140Z' 
    }
]
```

### Datetime comparison
A datetime can be compared with another using SurrealDB operators.

```surql
d"2025-07-03T07:18:52Z" < d"2025-07-03T07:18:52.84114Z";
```

```surql title="Response"
true
```

## Durations and datetimes

A duration can be used to alter a datetime.

```surql
CREATE event SET time = d"2025-07-03T07:18:52Z" + 2w;
```

```surql title="Response"
[
    { 
        id: event:`9ey7v8r0fd46xblf9dsf`, 
        time: d'2025-07-17T07:18:52Z' 
    }
]
```

Multi-part durations can also be used to modify datetimes.

```surql
CREATE event SET 
    time = d"2025-07-03T07:18:52.841147Z" + 1h30m20s1350ms;
```

```surql title="Response"
[
    { 
        id: event:5uuzy32t48yutxyszi7p, 
        time: d'2025-07-03T08:49:14.191147Z' 
    }
]
```

## Altering datetimes

_(since v3.0.2)_

Each value in a datetime can be set by using one of seven `time::set_` functions. Each of these function names ends with the part of the datetime that is modified, such as `time::set_year()` or `time::set_hour()`.

```surql
d'1970-01-01T00:00:00.000000100Z'.set_year(1914);
-- Output
d'1914-01-01T00:00:00.000000100Z'
```

As these functions do not modify an existing datetime but return a new one, they can be chained one after another.

```surql
d'1970-01-01T00:00:00.000000100Z'
    .set_year(1914)
    .set_month(6)
    .set_day(28);

-- Output
d'1914-06-28T00:00:00.000000100Z'
```

## See also

* [time](/docs/reference/query-language/functions/database-functions/time.md) functions, which enable extracting, altering, rounding, and grouping datetimes into specific time intervals