Overview
This is a memo on how to apply filters to created and changed fields in Drupal’s JSON:API.
Background
The following was used as a reference.
https://www.drupal.org/docs/core-modules-and-themes/core-modules/jsonapi-module/filtering
For example, when trying to filter only items updated on or after June 2, the following query did not work correctly.
?filter[a-label][condition][path]=changed&filter[a-label][condition][operator]=%3E%3D&filter[a-label][condition][value]=2025-06-02
Correct Method
The following article was helpful.
https://www.reddit.com/r/drupal/comments/1bdvu61/json_api_drupal_filter_on_date/
Note that timestamp fields (like created or changed) currently must use a timestamp for filtering:
For example, by using the timestamp 1748790000 for June 2, 2025, and using a query like the following, filtering was performed correctly.
?filter[a-label][condition][path]=changed&filter[a-label][condition][operator]=%3E%3D&filter[a-label][condition][value]=1748790000
Summary
We hope this is helpful when applying filters to created and changed fields in Drupal’s JSON:API.