Oktoberfest example uses improper index to lookup days per month

[clayheaton]

The Oktoberfest example has this lookup:

int[] daysPerMonth = new int[] {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
int[] daysPerMonthLeapYear = new int[] {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

and this function:

// Not really the exact date, but it's ok for this example
float getExactDate(int year, int month, int day) {
  boolean leapYear = false;

  if (year % 400 == 0) {
    leapYear = true;
  }
  else if (year % 100 == 0) {
    leapYear = false;
  }
  else if (year % 4 == 0) {
    leapYear = true;
  }

  if (leapYear) {
    return year + (month + (day - 1f)/daysPerMonthLeapYear[month])/12f;
  }
  else {
    return year + (month + (day - 1f)/daysPerMonth[month])/12f;
  }
}

The problem is that the return values from the function lookup the month instead of month-1, which leads to grabbing an incorrect value from the lookups. This can be fixed with this change to the function:

// Not really the exact date, but it's ok for this example
float getExactDate(int year, int month, int day) {
  boolean leapYear = false;

  if (year % 400 == 0) {
    leapYear = true;
  }
  else if (year % 100 == 0) {
    leapYear = false;
  }
  else if (year % 4 == 0) {
    leapYear = true;
  }

  if (leapYear) {
    return year + (month + (day - 1f)/daysPerMonthLeapYear[month-1])/12f;
  }
  else {
    return year + (month + (day - 1f)/daysPerMonth[month-1])/12f;
  }
}

[clayheaton]

Well... I see that the source data for the example has 0 as January... Anyhow, for anybody who finds this, if you are using 1 as january, then the fix I proposed addresses the issue.