Hello, i am using Boost V1.5.8 under vs 2010 with a german windows 7 64 bit. When I tried to calculate a time period I always ran into the same problem. The period is calculated one day too short. I wrote a little program to illustrate my problem. It's important that you change the value of the variable test to the current date. Is this a bug or do I use the library in an incorrect way? Thanks a lot, Georg #include "boost/date_time.hpp" #include <iostream> using namespace std; using namespace boost::gregorian; int main() { date today = day_clock::local_day(); date test(2015,6,23); // Change value to current date date first(1965,10,26); date_period period(first, today); if (!period.contains(test)) cout << "shouldn't be our testdate in the period? " << endl; }