# Date filter recognizing custom grok pattern?

**URL:** <https://discuss.elastic.co/t/date-filter-recognizing-custom-grok-pattern/24363>\
**Category:** Logstash\
**Created:** [June 25, 2015, 5:43pm UTC](https://discuss.elastic.co/t/date-filter-recognizing-custom-grok-pattern/24363 "2015-06-25T17:43:05Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![magnusbaeck](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/magnusbaeck/32/44943_2.png) [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)\
**Post date:** [June 25, 2015, 5:52pm UTC](https://discuss.elastic.co/t/date-filter-recognizing-custom-grok-pattern/24363/2 "2015-06-25T17:52:34Z")

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The date filter only accepts the Joda-Time tokens plus the Logstash-specific ISO8601, UNIX, UNIX\_MS, and TAI64N tokens. Grok patterns are not supported.

In your case you'll probably want to use one or a couple of filters to transform "2014-12-14 23:59:40.227 -8" to "2014-12-14 23:59:40.227 -0800" which Joda-Time's Z token will match (or if you can use ISO8601).

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_[View the full topic](https://discuss.elastic.co/t/date-filter-recognizing-custom-grok-pattern/24363)._