<abstract><p>The <bold>framework</bold> of this paper is behavioral finance and, more specifically, intertemporal choice when individuals exhibit decreasing impatience in their decision-making processes. After characterizing the two main types of decreasing impatience (moderately and strongly decreasing impatience), the <bold>main objective</bold> of this paper is to generalize these concepts when the criterion of time increase is given by an arbitrary function which describes such increments. In general, the <bold>methodology</bold> is mathematical calculus but particularly the concept of derivative according to the function which rules the increase of time. The <bold>main contribution</bold> of this paper is the characterization of this extension of the concept of decreasing impatience by using the aforementioned novel derivative and the well-known Prelec's index.</p></abstract>