Are you using the odata module from Mendix?
I found that there is no easy way to consume Mendix ODATA within Mendix ironically and the feature seems to be ,in my opinion, targeted more at allowing reporting tools to run on it. I’ve been using ODATA for a while now but found it to be lacking in a lot of ways.
While I don’t have a solution for your issue, I would suggest that you use published app services instead, they’re the easiest Mendix-to-Mendix Integration in my experience. You effectively export Microflows to be used from another Mendix app, it even comes with a mini-model when imported in the second app.
Edit: If any of the options in the comments work, could you let me know which one?
Hope this helps
The documentation for OData filtering says that you should use:
datetime’<epoch value here>’ datetime'1548793560'
So I think your query string is like this:
filter=day(changedDate) eq datetime'1548793560'
See the second table in the Filtering section: https://docs.mendix.com/refguide/odata-query-options#4-filtering
Found an answer to this issue in another post: https://forum.mendix.com/link/questions/92592