Duration analysis is a crucial, dynamically developing element of modern finance. Its changes have, from the very nature of things, a character of adaptation, which means that they are a response to financial markets and instruments development. In the 90's these changes are just enough important to talk about a substantial reorientation of the range of methods applied and major research areas. The article aims at presenting direction and scope of ongoing changes. To this end, three new theories will be described and illustrated with examples. It is the author's intention to facilitate similar analyses by offering three simple computer programs, available for interested readers at the address stated in the article.