A popular approach (Greenhill et al., 2010;Dunn et al., 2011) is to construct a time-tree with absolute (calendar) dates, using binary-coded lexical cognate data, and then to fit each trait of interest independently on the time-tree.
4 cognate data are available only for a handful of language families such as Indo-European, Austronesian and Niger-Congo (or its mammoth Bantu branch).