# Grok filter is not working properly

**URL:** <https://discuss.elastic.co/t/grok-filter-is-not-working-properly/229073>\
**Category:** Logstash\
**Created:** [April 21, 2020, 2:52pm UTC](https://discuss.elastic.co/t/grok-filter-is-not-working-properly/229073 "2020-04-21T14:52:12Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![Badger](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/badger/32/25190_2.png) [@Badger](https://discuss.elastic.co/u/Badger)\
**Post date:** [April 21, 2020, 3:55pm UTC](https://discuss.elastic.co/t/grok-filter-is-not-working-properly/229073/2 "2020-04-21T15:55:42Z")

</div>

I do not believe that the timestamp format you have is ISO8601. See [this](https://discuss.elastic.co/t/help-needed-in-grok/213827/2) for advice on how to develop a grok pattern.

---

_[View the full topic](https://discuss.elastic.co/t/grok-filter-is-not-working-properly/229073)._