Taking the temporal dimension into account in searching, i.e., using time of content creation as part of the search condition, is now gaining increasingly interest. However, in the case of web search and web warehousing, the timestamps (time of creation or creation of contents) of web pages and documents found on the web are in general not known or can not be trusted, and must be determined otherwise. In this paper, we describe approaches that enhance and increase the quality of existing techniques for determining timestamps based on a temporal language model. Through a number of experiments on temporal document collections we show how our new methods improve the accuracy of timestamping compared to the previous models.