Hi, I am hoping to use boost::date_time to do some date calculations. What I want to do is basically work out the number of days to a given date with various exclusions applied. eg. How many working days are there to christmas? using namespace boost::gregorian; int CalculateDaysToChristmas() { date_period someHoliday(date(2006, Dec, 01), date_duration(1)); date today(2006, Sep, 1); date christmas(2006, Dec, 25); int days = 0; for (day_iterator i = today; i != christmas; ++i) { if (is_weekday(*i) && !someHoliday.contains(*i)) ++days; } return days; } However, I can't find a simply way to work out is_weekday ... Secondly, is there some way to put every sunday in as a date_period? Thirdly, this doesn't seem very optimal ... is there a better way of doing this? Thanks, Andrew