Today I would like to present you operations related to date and time using Boost.DateTime library. This library contains set of
classes, templates and algorithms prepared for date and time related tasks. This article focuses on date operations. Time operations will be presented
in one of the future articles.
Example of usage some basic Boost.DateTime date operations you can see here:
Output of this example is (for day 2 January 2014):
All below operations will be based on boost::gregorian namespace. We created alias dateTime for that namespace for more convenient use.
In point I we are using universal_day() method for getting current day according to UTC time zone. Of course output of this and other date-related functions depends on date of invoking. Therefore you will get other output of your application every day you will invoke it.
universal_day() function returns Boost date class object which has lot of functions for date manipulation and displaying.
In point II we are using months class object to add one month to our current date. Thanks to overloading operator+() you can add date and months class objects and iterate through next and previous months. If you will add one month to the date 1-Jan-2014 you will receive 1-Feb-2014. However if you will add one month to date 31-Jan-2013 you will receive 28-Feb-2013 (because all dates are end days of consecutive months).
In point III we are using date_from_iso_string() method for conversion string formatted as "YYYYMMDD" to date class and display its value to standard output.
Point IV presents data_duration class object which allow you calculate time intervals. We are using two our date objects today and myBirthdayDate to calculate interval of live of person who was birth at 30-Jun-1985. Then we are using days() method of date_duration class to present calculated interval as number of days.
Point V present how to iterate through consecutive days using day_iterator class and overloaded operator++(. As you can see this iteration is adequate to mechanism of iteration between consecutive elements of STL containers. Thanks to that we have intuitive way to iterate throgh dates, too.
Of course DateTime library has more useful functions to operate on dates. Lots of details and examples you can find on the offical Boost.DateTime library documentation site here: http://www.boost.org/doc/libs/1_55_0/doc/html/date_time/examples.html
Example from this article you can find on our GitHub account here: https://github.com/xmementoit/CppAdventureExamples/tree/master/boost/dateTime
Example of usage some basic Boost.DateTime date operations you can see here:
Output of this example is (for day 2 January 2014):
All below operations will be based on boost::gregorian namespace. We created alias dateTime for that namespace for more convenient use.
In point I we are using universal_day() method for getting current day according to UTC time zone. Of course output of this and other date-related functions depends on date of invoking. Therefore you will get other output of your application every day you will invoke it.
universal_day() function returns Boost date class object which has lot of functions for date manipulation and displaying.
In point II we are using months class object to add one month to our current date. Thanks to overloading operator+() you can add date and months class objects and iterate through next and previous months. If you will add one month to the date 1-Jan-2014 you will receive 1-Feb-2014. However if you will add one month to date 31-Jan-2013 you will receive 28-Feb-2013 (because all dates are end days of consecutive months).
In point III we are using date_from_iso_string() method for conversion string formatted as "YYYYMMDD" to date class and display its value to standard output.
Point IV presents data_duration class object which allow you calculate time intervals. We are using two our date objects today and myBirthdayDate to calculate interval of live of person who was birth at 30-Jun-1985. Then we are using days() method of date_duration class to present calculated interval as number of days.
Point V present how to iterate through consecutive days using day_iterator class and overloaded operator++(. As you can see this iteration is adequate to mechanism of iteration between consecutive elements of STL containers. Thanks to that we have intuitive way to iterate throgh dates, too.
Of course DateTime library has more useful functions to operate on dates. Lots of details and examples you can find on the offical Boost.DateTime library documentation site here: http://www.boost.org/doc/libs/1_55_0/doc/html/date_time/examples.html
Example from this article you can find on our GitHub account here: https://github.com/xmementoit/CppAdventureExamples/tree/master/boost/dateTime
Boost is very big and hard to learn library. I appreciate that you would like to explain it here step by step.
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