# Date Period Calculations

Calculates if a date is in an 'irregular' collection of periods using period calculation functions.

      /*
      This example demonstrates a simple use of periods for the calculation
      of date information.

      The example calculates if a given date is a weekend or holiday
      given an exclusion set.  That is, each weekend or holiday is
      entered into the set as a time interval.  Then if a given date
      is contained within any of the intervals it is considered to
      be within the exclusion set and hence is a offtime.

      Output:
      Number Excluded Periods: 5
      20020202/20020203
      20020209/20020210
      20020212/20020212
      20020216/20020217
      In Exclusion Period: 20020216 --> 20020216/20020217
      20020223/20020224

      */

      #include "boost/date_time/gregorian/gregorian.hpp"
      #include <set>
      #include <algorithm>
      #include <iostream>

      typedef std::set<boost::gregorian::date_period> date_period_set;

      //Simple population of the exclusion set
      date_period_set
      generateExclusion()
      {
        using namespace boost::gregorian;
        date_period periods_array[] =
          { date_period(date(2002,Feb,2), date(2002,Feb,4)),//weekend of 2nd-3rd
            date_period(date(2002,Feb,9), date(2002,Feb,11)),
            date_period(date(2002,Feb,16), date(2002,Feb,18)),
            date_period(date(2002,Feb,23), date(2002,Feb,25)),
            date_period(date(2002,Feb,12), date(2002,Feb,13))//a random holiday 2-12
          };
        const int num_periods = sizeof(periods_array)/sizeof(date_period);

        date_period_set ps;
        //insert the periods in the set
        std::insert_iterator<date_period_set> itr(ps, ps.begin());
        std::copy(periods_array, periods_array+num_periods, itr );
        return ps;

      }

      int main()
      {
        using namespace boost::gregorian;

        date_period_set ps = generateExclusion();
        std::cout << "Number Excluded Periods: "  << ps.size() << std::endl;

        date d(2002,Feb,16);
        date_period_set::const_iterator i = ps.begin();
        //print the periods, check for containment
        for (;i != ps.end(); i++) {
          std::cout << to_iso_string(*i) << std::endl;
          //if date is in exclusion period then print it
          if (i->contains(d)) {
            std::cout << "In Exclusion Period: "
                << to_iso_string(d) << " --> " << to_iso_string(*i)
                << std::endl;
          }
        }

        return 0;

      }