Using the Post Grid Combo plugin, you can query older posts or order by date. This article gives you a clear idea of how to query older posts or order by date.
Click on the “Query Post” tab.
Now expand the “Order by” drop-down menu and select “date.” The Post Grid order is now updated by date.
Then, from the “Order” drop-down menu, choose “ascending.”
Now your “Post Grid” is showing older posts.