Introduction -- Header -- Construction -- Accessors -- Operators Introduction The class boost::local_time::local_time_period provides direct representation for ranges between two local times. Periods provide the ability to simplify some types of calculations by simplifying the conditional logic of the program. A period that is created with beginning and end points being equal, or with a duration of zero, is known as a zero length period. Zero length periods are considered invalid (it is perfectly legal to construct an invalid period). For these periods, the last point will always be one unit less that the begin point. Header #include "boost/date_time/local_time/local_time.hpp" //include all types plus i/o or #include "boost/date_time/local_time/local_time_types.hpp" //no i/o just types Construction Syntax Description Example local_time_period(...) Parameters: local_date_time beginning local_date_time end Create a period as [begin, end). If end is <= begin then the period will be defined as invalid. time_zone_ptr zone(new posix_time_zone("MST-07")); local_date_time beg(ptime(date(2005,Jan,1),hours(0)), zone); local_date_time end(ptime(date(2005,Feb,1),hours(0)), zone); // period for the entire month of Jan 2005 local_time_period ltp(beg, end); local_time_period(...) Parameters: local_date_time beginning time_duration length Create a period as [begin, begin+len) where end would be begin+len. If len is <= zero then the period will be defined as invalid. time_zone_ptr zone(new posix_time_zone("MST-07")); local_date_time beg(ptime(date(2005,Jan,1),hours(0)), zone); // period for the whole day of 2005-Jan-01 local_time_period ltp(beg, hours(24)); local_time_period(local_time_period rhs) Copy constructor local_time_period ltp1(ltp); Accessors Syntax Description Example local_date_time begin() Return first local_date_time of the period. time_zone_ptr zone(new posix_time_zone("MST-07")); local_date_time ldt((ptime(date(2005,Jan,1)),hours(0)), zone); local_time_period ltp(ldt, hours(2)); ltp.begin(); // => 2005-Jan-01 00:00:00 local_date_time last() Return last local_date_time in the period time_zone_ptr zone(new posix_time_zone("MST-07")); local_date_time ldt((ptime(date(2005,Jan,1),hours(0))), zone); local_time_period ltp(ldt, hours(2)); ltp.last(); // => 2005-Jan-01 01:59:59.999999999 local_date_time end() Return one past the last in period time_zone_ptr zone(new posix_time_zone("MST-07")); local_date_time ldt((ptime(date(2005,Jan,1),hours(0))), zone); local_time_period ltp(ldt, hours(2)); ltp.end(); // => 2005-Jan-01 02:00:00 time_duration length() Return the length of the local_time period. time_zone_ptr zone(new posix_time_zone("MST-07")); local_date_time ldt((ptime(date(2005,Jan,1),hours(0))), zone); local_time_period ltp(ldt, hours(2)); ltp.length(); // => 02:00:00 bool is_null() True if period is not well formed. eg: end less than or equal to begin. time_zone_ptr zone(new posix_time_zone("MST-07")); local_date_time beg((ptime(date(2005,Feb,1),hours(0))), zone); local_date_time end((ptime(date(2005,Jan,1),hours(0))), zone); local_time_period ltp(beg, end); ltp.is_null(); // => true bool contains(local_date_time) True if local_date_time is within the period. Zero length periods cannot contain any points time_zone_ptr zone(new posix_time_zone("MST-07")); local_date_time beg((ptime(date(2005,Jan,1),hours(0))), zone); local_date_time end((ptime(date(2005,Feb,1),hours(0))), zone); local_time_period jan_mst(beg, end); local_date_time ldt((ptime(date(2005,Jan,15),hours(12))), zone); jan_mst.contains(ldt); // => true local_time_period zero(beg, beg); zero.contains(beg); // false bool contains(local_time_period) True if period is within the period // using jan_mst period from previous example local_date_time beg((ptime(date(2005,Jan,7),hours(0))), zone); local_time_period ltp(beg, hours(24)); jan_mst.contains(ltp); // => true bool intersects(local_time_period) True if periods overlap // using jan_mst period from previous example local_date_time beg((ptime(date(2005,Jan,7),hours(0))), zone); local_date_time end((ptime(date(2005,Feb,7),hours(0))), zone); local_time_period ltp(beg, end); jan_mst.intersects(ltp); // => true local_time_period intersection(local_time_period) Calculate the intersection of 2 periods. Null if no intersection. // using jan_mst period from previous example local_date_time beg((ptime(date(2005,Jan,7),hours(0))), zone); local_date_time end((ptime(date(2005,Feb,7),hours(0))), zone); local_time_period ltp(beg, end); local_time_period res(jan_mst.intersection(ltp)); // res => 2005-Jan-07 00:00:00 through // 2005-Jan-31 23:59:59.999999999 (inclusive) local_time_period merge(local_time_period) Returns union of two periods. Null if no intersection. // using jan_mst period from previous example local_date_time beg((ptime(date(2005,Jan,7),hours(0))), zone); local_date_time end((ptime(date(2005,Feb,7),hours(0))), zone); local_time_period ltp(beg, end); local_time_period res(jan_mst.merge(ltp)); // res => 2005-Jan-07 00:00:00 through // 2005-Feb-06 23:59:59.999999999 (inclusive) local_time_period span(local_time_period) Combines two periods and any gap between them such that begin = min(p1.begin, p2.begin) and end = max(p1.end , p2.end). // using jan_mst period from previous example local_date_time beg((ptime(date(2005,Mar,1),hours(0))), zone); local_date_time end((ptime(date(2005,Apr,1),hours(0))), zone); local_time_period mar_mst(beg, end); local_time_period res(jan_mst.span(mar_mst)); // res => 2005-Jan-01 00:00:00 through // 2005-Mar-31 23:59:59.999999999 (inclusive) void shift(time_duration) Add duration to both begin and end. local_date_time beg((ptime(date(2005,Mar,1),hours(0))), zone); local_date_time end((ptime(date(2005,Apr,1),hours(0))), zone); local_time_period mar_mst(beg, end); mar_mst.shift(hours(48)); // mar_mst => 2005-Mar-03 00:00:00 through // 2005-Apr-02 23:59:59.999999999 (inclusive) Operators Syntax Description Example operator==, operator!= Equality operators. Periods are equal if ltp1.begin == ltp2.begin && ltp1.last == ltp2.last if (ltp1 == ltp2) {... operator< Ordering with no overlap. True if ltp1.end() less than ltp2.begin() if (ltp1 < ltp2) {... operator> Ordering with no overlap. True if ltp1.begin() greater than ltp2.end() if (ltp1 > ltp2) {... etc operator<=, operator>= Defined in terms of the other operators.