public abstract int getActualMinimum(int field);
public int getActualMinimum(int field) { Calendar tmp = (Calendar)clone(); int min = tmp.getGreatestMinimum(field); int end = tmp.getMinimum(field); tmp.set(field, min); for (; min > end; min--) { tmp.add(field, -1); if (tmp.get(field) != min - 1) break;  } return min; }
	public abstract int getActualMinimum(int field);