# Change date format on an existing field

**URL:** <https://discuss.elastic.co/t/change-date-format-on-an-existing-field/79265>\
**Category:** Elasticsearch\
**Created:** [March 20, 2017, 1:59pm UTC](https://discuss.elastic.co/t/change-date-format-on-an-existing-field/79265 "2017-03-20T13:59:14Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![dadoonet](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dadoonet/32/137187_2.png) [@dadoonet](https://discuss.elastic.co/u/dadoonet)\
**Post date:** [March 20, 2017, 2:10pm UTC](https://discuss.elastic.co/t/change-date-format-on-an-existing-field/79265/2 "2017-03-20T14:10:09Z")

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Please format your code using `</>` icon as explained in [this guide](https://discuss.elastic.co/t/about-the-elasticsearch-category/21). It will make your post more readable.

Or use markdown style like:

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````

You can't. You need to reindex.

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_[View the full topic](https://discuss.elastic.co/t/change-date-format-on-an-existing-field/79265)._