If you need to create the filter dynamically you will need to create a control which derives from the NewsView. Once you create a control which inherits it you can override CreateChildControls method and before the base implementation is called you can manipulate this.FilterExpression property to set the filter to proper date range.
All the best,
the Telerik team
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 Public Issue Tracking
system and vote to affect the priority of the items