Thus, temporal tagging has become a vibrant research area, and several new temporal taggers have been made available and new strategies have been developed.
as was shown in previous work (Mazur and Dale, 2010;Strötgen and Gertz, 2013;Bethard et al., 2016;Tabassum et al., 2016), different types of documents pose different challenges for temporal tagging such that domain-sensitive normalization strategies are required (Strötgen and Gertz, 2016).