# `IngestDateIndexNameProcessor` [interface-IngestDateIndexNameProcessor]

| Name | Type | Description |
| - | - | - |
| `date_formats` | string[] | An array of the expected date formats for parsing dates / timestamps in the document being preprocessed. Can be a java time pattern or one of the following formats: ISO8601, UNIX, UNIX_MS, or TAI64N. |
| `date_rounding` | string | How to round the date when formatting the date into the index name. Valid values are: `y` (year), `M` (month), `w` (week), `d` (day), `h` (hour), `m` (minute) and `s` (second). Supports template snippets. |
| `field` | [Field](./Field.md) | The field to get the date or timestamp from. |
| `index_name_format` | string | The format to be used when printing the parsed date into the index name. A valid java time pattern is expected here. Supports template snippets. |
| `index_name_prefix` | string | A prefix of the index name to be prepended before the printed date. Supports template snippets. |
| `locale` | string | The locale to use when parsing the date from the document being preprocessed, relevant when parsing month names or week days. |
| `timezone` | string | The timezone to use when parsing the date and when date math index supports resolves expressions into concrete index names. |