## org.jfree.data.time
Class Month

    java.lang.Object
      org.jfree.data.time.RegularTimePeriod
          org.jfree.data.time.Month

All Implemented Interfaces:
  java.io.Serializable, java.lang.Comparable, TimePeriod, org.jfree.date.MonthConstants

    public class Month

extends RegularTimePeriod
implements java.io.Serializable

Represents a single month. This class is immutable, which is a requirement for all `RegularTimePeriod` subclasses.

See Also:
  Serialized Form

Field Summary

Fields inherited from class org.jfree.data.time.RegularTimePeriod
`DEFAULT_TIME_ZONE, WORKING_CALENDAR`

Fields inherited from interface org.jfree.date.MonthConstants
`APRIL, AUGUST, DECEMBER, FEBRUARY, JANUARY, JULY, JUNE, MARCH, MAY, NOVEMBER, OCTOBER, SEPTEMBER`

Constructor Summary
`Month()` Constructs a new Month, based on the current system time.
`Month(java.util.Date time)` Constructs a new `Month` instance, based on a date/time and the default time zone.
`Month(java.util.Date time, java.util.TimeZone zone)` Constructs a new `Month` instance, based on a date/time and a time zone.
`Month(int month, int year)` Constructs a new month instance.
`Month(int month, Year year)` Constructs a new month instance.

Method Summary
`int` `compareTo(java.lang.Object o1)` Returns an integer indicating the order of this Month object relative to the specified object: negative == before, zero == same, positive == after.
`boolean` `equals(java.lang.Object obj)` Tests the equality of this Month object to an arbitrary object.
`long` `getFirstMillisecond()` Returns the first millisecond of the month.
`long` `getFirstMillisecond(java.util.Calendar calendar)` Returns the first millisecond of the month, evaluated using the supplied calendar (which determines the time zone).
`long` `getLastMillisecond()` Returns the last millisecond of the month.
`long` `getLastMillisecond(java.util.Calendar calendar)` Returns the last millisecond of the month, evaluated using the supplied calendar (which determines the time zone).
`int` `getMonth()` Returns the month.
`long` `getSerialIndex()` Returns a serial index number for the month.
`Year` `getYear()` Returns the year in which the month falls.
`int` `getYearValue()` Returns the year in which the month falls.
`int` `hashCode()` Returns a hash code for this object instance.
`RegularTimePeriod` `next()` Returns the month following this one.
`static Month` `parseMonth(java.lang.String s)` Parses the string argument as a month.
`void` `peg(java.util.Calendar calendar)` Recalculates the start date/time and end date/time for this time period relative to the supplied calendar (which incorporates a time zone).
`RegularTimePeriod` `previous()` Returns the month preceding this one.
`java.lang.String` `toString()` Returns a string representing the month (e.g.

Methods inherited from class org.jfree.data.time.RegularTimePeriod
`createInstance, downsize, getEnd, getFirstMillisecond, getLastMillisecond, getMiddleMillisecond, getMiddleMillisecond, getMiddleMillisecond, getStart`

Methods inherited from class java.lang.Object
`clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

Constructor Detail

### Month

    public Month()

  Constructs a new Month, based on the current system time.

### Month

    public Month(int month,
                 int year)

  Constructs a new month instance.

  Parameters:
    `month` - the month (in the range 1 to 12).
    `year` - the year.

### Month

    public Month(int month,
                 Year year)

  Constructs a new month instance.

  Parameters:
    `month` - the month (in the range 1 to 12).
    `year` - the year.

### Month

    public Month(java.util.Date time)

  Constructs a new `Month` instance, based on a date/time and the default time zone.

  Parameters:
    `time` - the date/time.

### Month

    public Month(java.util.Date time,
                 java.util.TimeZone zone)

  Constructs a new `Month` instance, based on a date/time and a time zone. The first and last millisecond values are initially pegged to the given time zone also.

  Parameters:
    `time` - the date/time.
    `zone` - the time zone (`null` not permitted).

Method Detail

### getYear

    public Year getYear()

  Returns the year in which the month falls.

  Returns:
    The year in which the month falls (as a Year object).

### getYearValue

    public int getYearValue()

  Returns the year in which the month falls.

  Returns:
    The year in which the month falls (as an int).

### getMonth

    public int getMonth()

  Returns the month. Note that 1=JAN, 2=FEB, ...

  Returns:
    The month.

### getFirstMillisecond

    public long getFirstMillisecond()

  Returns the first millisecond of the month. This will be determined relative to the time zone specified in the constructor, or in the calendar instance passed in the most recent call to the `peg(Calendar)` method.

  Specified by:
    `getFirstMillisecond` in class `RegularTimePeriod`
  Returns:
    The first millisecond of the month.
  See Also:
    `getLastMillisecond()`

### getLastMillisecond

    public long getLastMillisecond()

  Returns the last millisecond of the month. This will be determined relative to the time zone specified in the constructor, or in the calendar instance passed in the most recent call to the `peg(Calendar)` method.

  Specified by:
    `getLastMillisecond` in class `RegularTimePeriod`
  Returns:
    The last millisecond of the month.
  See Also:
    `getFirstMillisecond()`

### peg

    public void peg(java.util.Calendar calendar)

  Recalculates the start date/time and end date/time for this time period relative to the supplied calendar (which incorporates a time zone).

  Specified by:
    `peg` in class `RegularTimePeriod`
  Parameters:
    `calendar` - the calendar (`null` not permitted).
  Since:
    1.0.3

### previous

    public RegularTimePeriod previous()

  Returns the month preceding this one.

  Specified by:
    `previous` in class `RegularTimePeriod`
  Returns:
    The month preceding this one.

### next

    public RegularTimePeriod next()

  Returns the month following this one.

  Specified by:
    `next` in class `RegularTimePeriod`
  Returns:
    The month following this one.

### getSerialIndex

    public long getSerialIndex()

  Returns a serial index number for the month.

  Specified by:
    `getSerialIndex` in class `RegularTimePeriod`
  Returns:
    The serial index number.

### toString

    public java.lang.String toString()

  Returns a string representing the month (e.g. "January 2002").

  To do: look at internationalisation.

  Overrides:
    `toString` in class `RegularTimePeriod`
  Returns:
    A string representing the month.

### equals

    public boolean equals(java.lang.Object obj)

  Tests the equality of this Month object to an arbitrary object. Returns true if the target is a Month instance representing the same month as this object. In all other cases, returns false.

  Overrides:
    `equals` in class `java.lang.Object`
  Parameters:
    `obj` - the object (`null` permitted).
  Returns:
    `true` if month and year of this and object are the same.

### hashCode

    public int hashCode()

  Returns a hash code for this object instance. The approach described by Joshua Bloch in "Effective Java" has been used here:

  `http://developer.java.sun.com/developer/Books/effectivejava /Chapter3.pdf`

  Overrides:
    `hashCode` in class `java.lang.Object`
  Returns:
    A hash code.

### compareTo

    public int compareTo(java.lang.Object o1)

  Returns an integer indicating the order of this Month object relative to the specified object: negative == before, zero == same, positive == after.

  Specified by:
    `compareTo` in interface `java.lang.Comparable`
  Parameters:
    `o1` - the object to compare.
  Returns:
    negative == before, zero == same, positive == after.

### getFirstMillisecond

    public long getFirstMillisecond(java.util.Calendar calendar)

  Returns the first millisecond of the month, evaluated using the supplied calendar (which determines the time zone).

  Specified by:
    `getFirstMillisecond` in class `RegularTimePeriod`
  Parameters:
    `calendar` - the calendar (`null` not permitted).
  Returns:
    The first millisecond of the month.
  Throws:
    `java.lang.NullPointerException` - if `calendar` is `null`.
  See Also:
    `RegularTimePeriod.getLastMillisecond(Calendar)`

### getLastMillisecond

    public long getLastMillisecond(java.util.Calendar calendar)

  Returns the last millisecond of the month, evaluated using the supplied calendar (which determines the time zone).

  Specified by:
    `getLastMillisecond` in class `RegularTimePeriod`
  Parameters:
    `calendar` - the calendar (`null` not permitted).
  Returns:
    The last millisecond of the month.
  Throws:
    `java.lang.NullPointerException` - if `calendar` is `null`.
  See Also:
    `RegularTimePeriod.getFirstMillisecond(Calendar)`

### parseMonth

    public static Month parseMonth(java.lang.String s)

  Parses the string argument as a month.

  This method is required to accept the format "YYYY-MM". It will also accept "MM-YYYY". Anything else, at the moment, is a bonus.

  Parameters:
    `s` - the string to parse.
  Returns:
    `null` if the string is not parseable, the month otherwise.