Boost C++ Libraries of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

This is the documentation for an old version of boost. Click here for the latest Boost documentation.
C++ Boost

posix_time::ptime Documentation


Overall Index -- Gregorian Index -- Posix Time Index

ptime Documentation

Header -- Construction -- Construct from String -- Construct from Clock -- Construct from time_t -- Accessors -- Conversion To String -- Operators


The class boost::posix_time::ptime is the primary interface for time point manipulation. In general, the ptime class is immutable once constructed although it does allow assignment.

Class ptime is dependent on gregorian::date for the interface to the date portion of a time point.

Other techniques for creating times include time iterators.


#include "boost/date_time/posix_time/posix_time.hpp" //include all types plus i/o
#include "boost/date_time/posix_time/posix_time_types.hpp" //no i/o just types


ptime(date,time_duration) Construct from a date and offset ptime t1(date(2002,Jan,10), time_duration(1,2,3));
ptime t2(date(2002,Jan,10), hours(1)+nanosec(5));
ptime(ptime) Copy constructor ptime t3(t1)
ptime(special_values sv) Constructor for infinities, not-a-date-time ptime t1(neg_infin);
ptime t2(pos_infin);
ptime t3(not_a_date_time);

Construction From String

ptime time_from_string(const std::string&) From delimited string. std::string ts("2002-01-20 23:59:59.000");
ptime t(time_from_string(ts))
ptime from_iso_string(const std::string&) From non delimited iso form string. std::string ts("20020131T235959");
ptime t(from_iso_string(ts))

Construction From Clock

static ptime second_clock::local_time(); Get the local time, second level resolution, based on the time zone settings of the computer. ptime t(second_clock::local_time())
static ptime second_clock::universal_time() Get the UTC time. ptime t(second_clock::universal_day())

Construction From time_t

ptime from_time_t(time_t t); Converts a time_t into a ptime. ptime t = from_time_t(tt);


date date() const Get the date part of a time. date d(2002,Jan,10);
ptime t(d, hour(1)); --> 2002-Jan-10;
time_duration time_of_day() const Get the time offset in the day. date d(2002,Jan,10);
ptime t(d, hour(1));
t.time_of_day() --> 01:00:00;

Conversion To String

std::string to_simple_string(ptime) To YYYY-mmm-DD HH:MM:SS.fffffffff string where mmm 3 char month name. Fractional seconds only included if non-zero. 2002-Jan-01 10:00:01.123456789
std::string to_iso_string(ptime) Convert to form YYYYMMDDTHHMMSS,fffffffff where T is the date-time separator 20020131T100001,123456789
std::string to_iso_extended_string(ptime) Convert to form YYYY-MM-DDTHH:MM:SS,fffffffff where T is the date-time separator 2002-01-31T10:00:01,123456789


operator<< Stream output operator. Format of the date output is subject to the current localization settings. See I/O localization for more. date d(2002,Jan,1)
ptime t(d, hours(3)+minutes(2)+milliseconds(1));
std::cout << t << std::endl;//2002-Jan-01 03:02:00.001
operator==, operator!=,
operator>, operator<
operator>=, operator<=
A full complement of comparison operators t1 == t2, etc
ptime operator+(date_duration) const Return a ptime adding a day offset date d(2002,Jan,1);
ptime t(d,minutes(5));
date_duration dd(1);
ptime t2 = t + dd;
ptime operator-(date_duration) const Return a ptime subtracting a day offset date d(2002,Jan,1);
ptime t(d,minutes(5));
date_duration dd(1);
ptime t2 = t - dd;
ptime operator+(time_duration) const Return a ptime adding a time duration date d(2002,Jan,1);
ptime t(d,minutes(5));
ptime t2 = t + hours(1) + minutes(2);
ptime operator-(time_duration) const Return a ptime subtracting a time duration date d(2002,Jan,1);
ptime t(d,minutes(5));
ptime t2 = t - minutes(2);
time_duration operator-(ptime) const Take the difference between two times. date d(2002,Jan,1);
ptime t1(d,minutes(5));
ptime t2(d,seconds(5));
time_duration t3 = t2 - t1;//negative result

Last modified: Mon Jan 19 21:49:15 MST 2004 by Jeff Garland © 2000-2002