kdate - A Date Object  (version 1.2)

kdate is a C++ class that implements a date object.

General:

  A kdate object holds a date in the range 1/1/1900 to 12/31/2099.
  Currently, kdate only implements a subset of a full-featured date object.
  In any sample code below, presume identifiers that start with:
    d are of type kdate
    s are of type kstring
    n are of type long

kdate has four constructor functions:

  1. A constructor with no arg; creates a 1/1/1900 date
     kdate d1;
  2. A constructor with a c style string as an initial value
     kdate d2("6/10/95");
  3. A constructor with a kstring as an initial value
     kdate d3(s1);
  4. A constructor with a month, day and year as an initial value
     kdate d4(m, d, y);
  The constructors with string arguments assume strings of the form "m/d/y"
  where m is the 1 or two digit month, d is the 1 or 2 digit day,
  and y is a 2 or four digit year.
  Two digit years are converted to four digit years as follows:
  if y, a two digit year is in the range first_two_digit_year to 99,
  add 1900 to y, else add 2000 to y. first_two_digit_year is set to 50.

There is not a kdate destructor; no need for it; no dynamic memory.

There are six member functions:
  long operator - (kdate & d);
    e.g. n_days = d3 - d2; // determine the number of days between dates
  kdate operator + (long delta_days);
    e.g. d1 = d2 + 100;    // d2 is 100 days after d1
  kdate operator - (long delta_days);
    e.g. d1 = d2 - 100;    // d2 is 100 days before d1
  kstring mm_dd_yy();      // converts kdate to a kstring in mm/dd/yy format
    e.g. cout << d2.mm_dd_yy() << endl; // displays 06/10/95
  void get_m_d_y(int & month, int & day, int & year);
    e.g. d2.get(m, d, y);  // sets m, d, and y to month, day & year in d2
  int dow();               // day of week, 0 for sunday to 6 for saturday
    e.g. cout << d4.mm_dd_yy() << " is on " << day_name[d4.dow()] << endl;

There is a global function:
  long daynum(int month, int day, int year); // returns days since 1/1/1900

There is one global variable (see text above about first_two_digit_year)
  int first_two_digit_year = 50;

There is one global const:
  char * day_name[7] = {"SUN", "MON", "TUE", "WED", "THU", "FRI", "SAT"};