boost::date_time. I've cursed at it in the beginning, but it does things the Right Way, and I've been saved a number of times by its fighting back against short

boost::date_time. I've cursed at it in the beginning, but it does things the Right Way, and I've been saved a number of times by its fighting back against shortcuts (like using Unix time - the issues identified in the article are real and a good summary, but the solution only works for the case where you need to work within a limited time span, from 1970 until a few decades into this century.)