The relevance or ranking of various dynamically-determined instances of content can be adjusted or otherwise improved based on aspects such as the freshness or seasonality of the content. In many conventional relevance or ranking algorithms, factors such as popularity, performance, and profit are used to determine which content to present to a user, as well as how to display the selected content. Such algorithms do not necessarily reflect domain-specific knowledge very well, and thus fail to accurately select content that is of differing levels appeal at various ages of the content and/or during various seasons of the year. Freshness and/or seasonality adjustment scores can be used to generate improved relevance, selection, or ranking determinations for various categories of content.