There are many commercial tools that address various aspects of the Year 2000 problem. None of these tools, however, addresses the closely related leap-year problem. In this paper, we provide experimental results that suggest that the leap-year problem can be addressed by plan-based techniques for automated concept recovery. In particular, we provide representative code fragments illustrating the leap-year problem, and we show the results of an empirical study that provides evidence that a plan-based approach can efficiently recognize both correct and incorrect leap-year computations and that the needed plan library is likely to be tractable in size. This paper furthermore argues that plan-based techniques are in fact mature enough to make a significant contribution to the Year 2000 problem itself, despite none of the existing tools making any documented use of these plan-based techniques.