Date Iterators Introduction -- Header -- Overview Introduction Date iterators provide a standard mechanism for iteration through dates. Date iterators are a model of Bidirectional Iterator and can be used to populate collections with dates and other date generation tasks. For example, the print month example iterates through all the days in a month and prints them. All of the iterators here derive from boost::gregorian::date_iterator. Header #include "boost/date_time/gregorian/gregorian.hpp" //include all types plus i/o or #include "boost/date_time/gregorian/gregorian_types.hpp" //no i/o just types Overview Syntax Description Example date_iterator Common (abstract) base class for all day level iterators. day_iterator(date start_date, int day_count=1) Iterate day_count days at a time. This iterator does not provide postfix increment/decrement operators. Only prefix operators are provided. day_iterator day_itr(date(2005,Jan,1)); ++d_itr; // 2005-Jan-02 day_iterator 2day_itr(date(2005,Feb,1),2); ++2d_itr; // 2005-Feb-03 week_iterator(...) Parameters: date start_date int week_offset (defaults to 1) Iterate week_offset weeks at a time. This iterator does not provide postfix increment/decrement operators. Only prefix operators are provided. week_iterator wk_itr(date(2005,Jan,1)); ++wk_itr; // 2005-Jan-08 week_iterator 2wk_itr(date(2005,Jan,1),2); ++2wk_itr; // 2005-Feb-15 month_iterator(...) Parameters: date start_date int month_offset (defaults to 1) Iterate month_offset months. There are special rules for handling the end of the month. These are: if start date is last day of the month, always adjust to last day of the month. If date is beyond the end of the month (e.g. Jan 31 + 1 month) adjust back to end of month (for more details and examples of this, see Reversibility of Operations Pitfall. NOTE: the month_iterator is not effected by this pitfall.) This iterator does not provide postfix increment/decrement operators. Only prefix operators are provided. month_iterator m_itr(date(2005,Jan,1)); ++m_itr; // 2005-Feb-01 month_iterator 2m_itr(date(2005,Feb,1),2); ++2m_itr; // 2005-Apr-01 year_iterator(...) Parameters: date start_date int year_offset (defaults to 1) Iterate year_offset years. The year_iterator will always land on the day of the date parameter except when date is Feb 28 in a non-leap year. In this case the iterator will return Feb 29 for leap years (eg: 2003-Feb-28, 2004-Feb-29, 2005-Feb-28). This iterator does not provide postfix increment/decrement operators. Only prefix operators are provided. year_iterator y_itr(date(2005,Jan,1)); ++y_itr; // 2006-Jan-01 year_iterator 2y_itr(date(2005,Feb,1),2); ++2y_itr; // 2007-Feb-01