[java] Java Calendar, getting current month value, clarification needed

Calendar.getInstance().get(Calendar.MONTH);

is zero based, 10 is November. From the javadoc;

public static final int MONTH Field number for get and set indicating the month. This is a calendar-specific value. The first month of the year in the Gregorian and Julian calendars is JANUARY which is 0; the last depends on the number of months in a year.

Calendar.getInstance().get(Calendar.JANUARY);

is not a sensible thing to do, the value for JANUARY is 0, which is the same as ERA, you are effectively calling;

Calendar.getInstance().get(Calendar.ERA);