# isodow — DuckDB 1.5.5

Extract the isodow component from a date or timestamp

- Reference: /products/haybarn/functions/releases/duckdb-1.5.5/isodow/
- JSON: /products/haybarn/functions/api/v1/duckdb-1.5.5/functions/isodow.json
- Snapshot ID: duckdb-1.5.5
- Engine: duckdb v1.5.5
- Source ID: d8cdaa33fd
- Binary SHA-256: 8463eb26527b278109cfddffc4606e1019ebefcfe2eac75efc53c76ed8f282d5
- Captured: 2026-09-05T18:37:40.699Z
- Source: https://github.com/duckdb/duckdb/releases/tag/v1.5.5
- Loaded extensions: autocomplete, core_functions, icu, json, parquet, shell

## Interpretation

- Choose a snapshot matching the target engine and build. The default is captured from the published Haybarn WASM package used by the browser playground. Historical native snapshots are also available.
- Availability is an observation in the recorded build and extension profile, not a guarantee of support in every installation or in WASM.
- Types and descriptions are declarations from duckdb_functions(). Binding can specialize result types. Null means not supplied by the catalog; do not invent defaults, optionality, argument mode, or table output columns.
- Raw parameter arrays preserve catalog order for scalar/aggregate/macro functions. Raw table arguments are alphabetical. Use callingConvention for engine-confirmed positional order and named arguments; null modes are unrecorded. Named does not mean optional. Macro defaults and special named variadic behavior are not supplied by duckdb_functions().
- Catalog examples are source material and may require data or extensions. runnableExamples contains separately verified SQL for the pinned WASM package; sample-data adaptations and guide examples are labeled separately.
- Guide annotations and recipes are separate editorial content. The browser runner always uses Haybarn WASM 1.5.5-rc3, independently of the documentation snapshot.
- All URLs beginning with / are relative to the origin hosting this document. Exports require no JavaScript, cookies, API key, or browser engine.

## Overloads

### overload-e865e35ffa3d5d6c

Kind: scalar. Parameter order: catalog-order.

```text
isodow(ts: DATE) → BIGINT
```

Link: /products/haybarn/functions/releases/duckdb-1.5.5/isodow/#overload-e865e35ffa3d5d6c

| Argument | Catalog type | Calling mode |
| --- | --- | --- |
| ts | DATE | not recorded |

Declared return type: BIGINT. Variadic argument type: none declared.
Stability: CONSISTENT. Declared side effects: false.

### overload-56267af2c532e5aa

Kind: scalar. Parameter order: catalog-order.

```text
isodow(ts: INTERVAL) → BIGINT
```

Link: /products/haybarn/functions/releases/duckdb-1.5.5/isodow/#overload-56267af2c532e5aa

| Argument | Catalog type | Calling mode |
| --- | --- | --- |
| ts | INTERVAL | not recorded |

Declared return type: BIGINT. Variadic argument type: none declared.
Stability: CONSISTENT. Declared side effects: false.

### overload-7fa6e4ffdefbcd30

Kind: scalar. Parameter order: catalog-order.

```text
isodow(ts: TIMESTAMP) → BIGINT
```

Link: /products/haybarn/functions/releases/duckdb-1.5.5/isodow/#overload-7fa6e4ffdefbcd30

| Argument | Catalog type | Calling mode |
| --- | --- | --- |
| ts | TIMESTAMP | not recorded |

Declared return type: BIGINT. Variadic argument type: none declared.
Stability: CONSISTENT. Declared side effects: false.

### overload-d40d151da54d605c

Kind: scalar. Parameter order: catalog-order.

```text
isodow(ts: TIMESTAMP WITH TIME ZONE) → BIGINT
```

Link: /products/haybarn/functions/releases/duckdb-1.5.5/isodow/#overload-d40d151da54d605c

| Argument | Catalog type | Calling mode |
| --- | --- | --- |
| ts | TIMESTAMP WITH TIME ZONE | not recorded |

Declared return type: BIGINT. Variadic argument type: none declared.
Stability: CONSISTENT. Declared side effects: false.


## Guide recipes

No guide recipes.

## Engine catalog examples

Source examples may require additional data or extensions. Expressions are wrapped in SELECT; execution verification is not recorded.

Reported for: overload-e865e35ffa3d5d6c, overload-56267af2c532e5aa, overload-7fa6e4ffdefbcd30, overload-d40d151da54d605c

```sql
SELECT isodow(timestamp '2021-08-03 11:59:44.123456');
```

## Runnable examples

Executed successfully in Haybarn WASM 1.5.5-rc3. Sample data and guide examples are separate from the original catalog.

```sql
SELECT isodow(timestamp '2021-08-03 11:59:44.123456');
```

## Additional DuckDB documentation

- [Date Part Functions](https://duckdb.org/docs/current/sql/functions/datepart#isodowdate)

## In other engines

### Presto



Presto:

```sql
DAY_OF_WEEK(CAST('2012-08-08 01:00:00' AS TIMESTAMP))
```

Haybarn / DuckDB:

```sql
ISODOW(CAST('2012-08-08 01:00:00' AS TIMESTAMP))
```

Translation from [SQLGlot](https://github.com/tobymao/sqlglot/blob/3086608e6fd4c41c02dfba47171608d2b193fce2/tests/dialects/test_presto.py#L414).

### Snowflake: dayofweekiso()



Snowflake:

```sql
DAYOFWEEKISO(foo)
```

Haybarn / DuckDB:

```sql
ISODOW(foo)
```

Translation from [SQLGlot](https://github.com/tobymao/sqlglot/blob/3086608e6fd4c41c02dfba47171608d2b193fce2/tests/dialects/test_snowflake.py#L2462).

## Observed availability

| Snapshot | Observed | Overloads | JSON |
| --- | --- | --- | --- |
| haybarn-1.5.5-rc3 | present | 4 | [reference](/products/haybarn/functions/api/v1/haybarn-1.5.5-rc3/functions/isodow.json) |
| duckdb-1.5.5 | present | 4 | [reference](/products/haybarn/functions/api/v1/duckdb-1.5.5/functions/isodow.json) |
| duckdb-1.4.4 | present | 4 | [reference](/products/haybarn/functions/api/v1/duckdb-1.4.4/functions/isodow.json) |
| duckdb-1.3.2 | present | 4 | [reference](/products/haybarn/functions/api/v1/duckdb-1.3.2/functions/isodow.json) |

Engine catalog documentation is derived from MIT-licensed Haybarn and DuckDB. [Notices](/third-party-notices.txt).