I'd like to limit my post grid so that it only queries posts in a certain date range. In other words, if a post is more than 30 days old it will no longer be queried. I'm guessing I could do this under the Query Post tab in the More Query Parameter field but I'm not sure what arguments to use. Does anyone have any idea how to do this? Thanks in advance for the help!
Welcome to our forum.
I understand your issue, but "More Query Parameter" field seems still not ready for complex query,
But there is filter hook for query argument so you can add your own parameter, please see the documentation
https://pickplugins.com/documentation/post-grid/filter-hooks/post_grid_query_args/
https://codex.wordpress.org/Class_Reference/WP_Query#Date_Parameters
Let me know for more help.
Regards