Can you confirm the Sitefinity version used.
Generally speaking there is a filter that you can use in the right side bar specifying the period
, or sort them descending by Publication date
In addition, can you see that blog posts at least on the Frontend? If no, you can try to query the Blog posts
using the API filtering them by Publication Date and modify it
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Sitefinity CMS Ideas&Feedback Portal
and vote to affect the priority of the items