/* java.util.TimeZone
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 Free Software Foundation, Inc.

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 02110-1301 USA.

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 making a combined work based on this library.  Thus, the terms and
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 permission to link this library with independent modules to produce an
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 exception statement from your version. */

package java.util;

/**
 * This class represents a time zone offset and handles daylight savings.
 * 
 * You can get the default time zone with <code>getDefault</code>. This
 * represents the time zone where program is running.
 * 
 * Another way to create a time zone is <code>getTimeZone</code>, where you
 * can give an identifier as parameter. For instance, the identifier of the
 * Central European Time zone is "CET".
 * 
 * With the <code>getAvailableIDs</code> method, you can get all the supported
 * time zone identifiers.
 * 
 * @see Calendar
 * @see SimpleTimeZone
 * @author Jochen Hoenicke
 */
public abstract class TimeZone {

	/**
	 * Constant used to indicate that a short timezone abbreviation should be
	 * returned, such as "EST"
	 */
	public static final int SHORT = 0;

	/**
	 * Constant used to indicate that a long timezone name should be returned,
	 * such as "Eastern Standard Time".
	 */
	public static final int LONG = 1;

	/**
	 * The time zone identifier, e.g. PST.
	 */
	private String ID;

	/**
	 * The default time zone, as returned by getDefault.
	 */

	private static TimeZone defaultZone0;

	public TimeZone() {
	}

	/**
	 * Gets all available IDs.
	 * 
	 * @return An array of all supported IDs.
	 */
	public static String[] getAvailableIDs() {
		String[] jopId = new String[1];
		jopId[0] = "joptimezone";
		return jopId;
	}

	/**
	 * Returns the time zone under which the host is running. This can be
	 * changed with setDefault.
	 * 
	 * @return A clone of the current default time zone for this host.
	 * @see #setDefault
	 */
	public static TimeZone getDefault() {

		return defaultZone0;
	}

	/**
	 * Gets the identifier of this time zone. For instance, PST for Pacific
	 * Standard Time.
	 * 
	 * @returns the ID of this time zone.
	 */
	public String getID() {
		return ID;
	}

	/**
	 * Gets the time zone offset, for current date, modified in case of daylight
	 * savings. This is the offset to add to UTC to get the local time.
	 * 
	 * @param era
	 *            the era of the given date
	 * @param year
	 *            the year of the given date
	 * @param month
	 *            the month of the given date, 0 for January.
	 * @param day
	 *            the day of month
	 * @param dayOfWeek
	 *            the day of week
	 * @param milliseconds
	 *            the millis in the day (in local standard time)
	 * @return the time zone offset in milliseconds.
	 */
	public abstract int getOffset(int era, int year, int month, int day,
			int dayOfWeek, int milliseconds);

	/**
	 * Gets the time zone offset, ignoring daylight savings. This is the offset
	 * to add to UTC to get the local time.
	 * 
	 * @return the time zone offset in milliseconds.
	 */
	public abstract int getRawOffset();

	/**
	 * Gets the TimeZone for the given ID.
	 * 
	 * @param ID
	 *            the time zone identifier.
	 * @return The time zone for the identifier or GMT, if no such time zone
	 *         exists.
	 */
	// FIXME: XXX: JCL indicates this and other methods are synchronized.
	public static TimeZone getTimeZone(String ID) {

		return defaultZone0;

	}

	/**
	 * Returns true, if this time zone uses Daylight Savings Time.
	 */
	public abstract boolean useDaylightTime();

}