Hi there, I use the date_time library quite a bit, due to its power and ease of use (quote me on that ;-) . One of the things that make working with it a bit awkward (and I presume the same is true for some other Boost libraries) is that it doesn't use Boost integer types througout the entire library. E.g., the boost::posix_time::hours class expects a "long" , which on most (but probably not all) systems, will be the same as a boost::int32_t (and shouldn't it be an unsigned type ?). This means that, if I really want to adhere to each library's specifications, I have to support three integer type systems in an application: std::size_t for containers, boost::(u)intXX_t and the "traditional" (unsigned) short/int/long types. Instead I'm now just giving the hour/minute/... classes an int32_t . Having a common set of integer types throughout Boost would be high on my wishlist. Kind Regards / Mit freundlichen Gruessen, Ruediger Berlich