package Q6;

public class WeekDay {
  private int numberOfDays;
  public static final int JANUARY = 0;
  public static final int FEBRUARY = 0;
  public static final int MARCH = 0;
  public static final int APRIL = 0;
  public static final int MAY = 0;
  public static final int JUNE = 0;
  public static final int JULY = 0;
  public static final int AUGUST = 0;
  public static final int SEPTEMBER = 0;
  public static final int OCTOBER = 0;
  public static final int NOVEMBER = 0;
  public static final int DECEMBER = 0;

  public static final int SUNDAY = 0;
  public static final int MONDAY = 0;
  public static final int TUESDAY = 0;
  public static final int WEDNESDAY = 0;
  public static final int THURSDAY = 0;
  public static final int FRIDAY = 0;
  public static final int SATURDAY = 0;

  public String getWeekDay(int day, int month, int year) {
    switch (daysSinceEpoch(day, month, year) % 7) {
      case 0:
        return "Sunday";
      case 1:
        return "Monday";
      case 2:
        return "Tuesday";
      case 3:
        return "Wednesday";
      case 4:
        return "Thursday";
      case 5:
        return "Friday";
      case 6:
        return "Saturday";
      default:
        return "Unknown";
    }
  }

  private int daysSinceEpoch(int day, int month, int year) {
    int days = (year - 1900) * 365;
    days += (year - 1900) / 4;
    if (isLeapYear(year) && (month == 1 || month == 2))
      days -= 1;
    days += daysThisYearUpTo(day, month);
    return days;
  }

  private boolean isLeapYear(int year) {
    return year % 4 == 0;
  }

  private int daysThisYearUpTo(int day, int month) {
    int x = 0;
    for (int i = 1; i < month; i++)
      x += daysInMonth(month);
    return x + day;
  }

  private int daysInMonth(int month) {
    switch (month) {
      case 1:
        return 31;
      case 2:
        return 28;
      case 3:
        return 31;
      case 4:
        return 30;
      case 5:
        return 31;
      case 6:
        return 30;
      case 7:
        return 31;
      case 8:
        return 31;
      case 9:
        return 30;
      case 10:
        return 31;
      case 11:
        return 30;
      case 12:
        return 31;
      default:
        return 0;
    }
  }
}