Extending the OBDA approach - where multiple data sources are exposed to users via a unified conceptual schema based on description logics - to also cover temporal reasoning has been a long standing goal, with many proposals over the last decades. To the best of our knowledge, these have yet to yield results in the form of systems or prototypes. As part of our ongoing work towards practical applicability, we identify here a number of key problems, which we believe have not been addressed suitably by previous works. Among these is the ability to deal with heterogeneous representations of time, the ability to deal with temporal inconsistencies, either due to missing value samples or conflicting values for a given time point and finally we also seek a suitable query language, where we in particular want compositionality - the ability to use the output of queries to form new temporal views on the data. We present here our initial ideas on how to meet these challenges.