The `date_index_name` processor is used to point documents to the correct time-based index based on the date or timestamp field within the document. The processor sets the `_index` metadata field to a [date math]({{site.url}}{{site.baseurl}}/field-types/supported-field-types/date/#date-math) index name expression. Then the processor fetches the date or timestamp from the `field` field in the document being processed and formats it into a date math index name expression. The extracted date, `index_name_prefix` value, and `date_rounding` value are then combined to create the date math index expression. For example, if the `field` field contains the value `2023-10-30T12:43:29.000Z` and `index_name_prefix` is set to `week_index-` and `date_rounding` is set to `w`, then the date math index name expression is `week_index-2023-10-30`. You can use the `date_formats` field to specify how the date in the date math index expression should be formatted.
The following is the syntax for the `date_index_name` processor:
```json
{
"date_index_name": {
"field": "your_date_field or your_timestamp_field",
"date_rounding": "rounding_value"
}
}
```
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## Configuration parameters
The following table lists the required and optional parameters for the `date_index_name` processor.
Parameter | Required/Optional | Description |
|-----------|-----------|-----------|
`field` | Required | The date or timestamp field in the incoming document. Supports [template snippets]({{site.url}}{{site.baseurl}}/ingest-pipelines/create-ingest/#template-snippets). |
`date_rounding` | Required | The rounded date format within the index name . Valid values are `y` (year), `M` (month), `w` (week), `d` (day), `h` (hour), `m` (minute), and `s` (second). |
`date_formats` | Optional | An array of date formats used to parse the date or timestamp field. Valid options include a java time pattern or one of the following formats: ISO8601, UNIX, UNIX_MS, or TAI64N. Default is `yyyy-MM-dd'T'HH:mm:ss.SSSXX`. |
`index_name_format` | Optional | The date format. Default is `yyyy-MM-dd`. Supports [template snippets]({{site.url}}{{site.baseurl}}/ingest-pipelines/create-ingest/#template-snippets). |
`index_name_prefix` | Optional | The index name prefix to append before the date. Supports [template snippets]({{site.url}}{{site.baseurl}}/ingest-pipelines/create-ingest/#template-snippets).
`description` | Optional | A brief description of the processor. |
`if` | Optional | A condition for running this processor. |
`ignore_failure` | Optional | If set to `true`, failures are ignored. Default is `false`. |
`locale` | `locale` | Optional | The locale to use when parsing the month name and week day of the date. Default is `ENGLISH`. Supports [template snippets]({{site.url}}{{site.baseurl}}/ingest-pipelines/create-ingest/#template-snippets). |
`on_failure` | Optional | A list of processors to run if the processor fails. |
`tag` | Optional | An identifier tag for the processor. Useful for debugging to distinguish between processors of the same type. |
`timezone` | Optional | The time zone to use when parsing the date. Default is `UTC`. |
## Using the processor
Follow these steps to use the processor in a pipeline.
**Step 1: Create a pipeline.**
The following query creates a pipeline, named `date-index-name1`, that uses the `date_index_name` processor to index logs into monthly indexes:
```json
PUT /_ingest/pipeline/date-index-name1
{
"description": "Create weekly index pipeline",
"processors": [
{
"date_index_name": {
"field": "date_field",
"index_name_prefix": "week_index-",
"date_rounding": "w",
"date_formats": ["YYYY-MM-DD"]
}
}
]
}
```
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**Step 2 (Optional): Test the pipeline.**
It is recommended that you test your pipeline before you ingest documents.
{: .tip}
To test the pipeline, run the following query:
```json
POST _ingest/pipeline/date-index-name1/_simulate
{
"docs": [
{
"_index": "testindex1",
"_id": "1",
"_source": {
"date_field": "2023-10-30"
}
}
]
}
```
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#### Response
The following example response confirms that the pipeline is working as expected:
The following query ingests a document into an index named `testindex1`:
```json
PUT testindex1/_doc/1?pipeline=date-index-name1
{
"date_field": "2023-10-30"
}
```
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#### Response
The request indexes the document into the index `week_index-2023-10-23` and will index all documents with a timestamp within that week into the same index because the pipeline rounds by week.
```json
{
"_index": "week_index-2023-10-30",
"_id": "1",
"_version": 4,
"result": "updated",
"_shards": {
"total": 2,
"successful": 1,
"failed": 0
},
"_seq_no": 3,
"_primary_term": 1
}
```
**Step 4 (Optional): Retrieve the document.**
To retrieve the document, run the following query:
