---
title: new_index
description: This setting may be a valid Elasticsearch date math string. A date math name takes the following form: The following example shows different forms of...
url: https://www.elastic.co/elastic/docs-builder/docs/3028/reference/elasticsearch/curator/option_new_index
products:
  - Elasticsearch
  - Elasticsearch Curator
---

# new_index
<note>
  This optional setting is only used by the [rollover](https://www.elastic.co/elastic/docs-builder/docs/3028/reference/elasticsearch/curator/rollover) action.
</note>

```yaml
description: >-
  Rollover the index associated with alias 'name'.  Specify new index name using
  date math.
options:
  name: aliasname
  new_index: "<prefix-{now/d}-1>"
  conditions:
    max_age: 1d
  wait_for_active_shards: 1
```

<important>
  A new index name for rollover should still end with a dash followed by an incrementable number, e.g. `my_new_index-1`, or if using date math, `<prefix-{now/d}-1>` or `<prefix-{now/d}-000001>`
</important>


## date_math

This setting may be a valid [Elasticsearch date math string](https://docs-v3-preview.elastic.dev/elastic/docs-builder/docs/3028/reference/elasticsearch/rest-apis/api-conventions#api-date-math-index-names).
A date math name takes the following form:
```sh
<static_name{date_math_expr{date_format|time_zone}}>
```


|                  |                                                                                                 |
|------------------|-------------------------------------------------------------------------------------------------|
| `static_name`    | is the static text part of the name                                                             |
| `date_math_expr` | is a dynamic date math expression that computes the date dynamically                            |
| `date_format`    | is the optional format in which the computed date should be rendered. Defaults to `yyyy.MM.dd`. |
| `time_zone`      | is the optional time zone . Defaults to `utc`.                                                  |

The following example shows different forms of date math names and the final form they resolve to given the current time is 22rd March 2024 noon utc.

| Expression                                   | Resolves to           |
|----------------------------------------------|-----------------------|
| `<logstash-{now/d}>`                         | `logstash-2024.03.22` |
| `<logstash-{now/M}>`                         | `logstash-2024.03.01` |
| `<logstash-{now/M{yyyy.MM}}>`                | `logstash-2024.03`    |
| `<logstash-{now/M-1M{yyyy.MM}}>`             | `logstash-2024.02`    |
| `<logstash-{now/d{yyyy.MM.dd&#124;+12:00}}>` | `logstash-2024.03.23` |

There is no default value for `new_index`.