bigdate.java

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    /**
     * Get day number in the year for this BigDate.
     *
     * @return day number Jan 01 = 1, 1 to 366
     */
    public final int getDDD()
        {
        return ( ordinal == NULL_ORDINAL )
               ? 0
               : ( ordinal - jan01OfYear( yyyy ) + 1 );
        }

    /**
     * Get java.util.Date object corresponding to this BigDate,
     *
     * @param timeZone We consider this BigDate to have an implied time of 0:00 in this timeZone.
     * @return Date or null Result is undefined if BigDate is outside the range handled by Date.
     * @see #getLocalTimeStamp
     * @see #getUTCTimeStamp
     * @see #getTimeStamp
     * @see #getUTCDate
     * @see #getLocalDate
     */
    public final java.util.Date getDate( TimeZone timeZone )
        {
        return ordinal == NULL_ORDINAL
               ? null
               : new java.util.Date( getTimeStamp( timeZone ) );
        }

    /**
     * Get day of week for this BigDate. It is zero-based starting with Sunday.
     *
     * @return day of week 0=Sunday 1=Monday 2=Tuesday 3=Wednesday 4=Thursday 5=Friday 6=Saturday WARNING: not
     *         compatible with 1=Calendar.SUNDAY
     * @see #getCalendarDayOfWeek
     * @see #getISODayOfWeek
     * @see #dayOfWeek
     */
    public final int getDayOfWeek()
        {
        return dayOfWeek( ordinal );
        }

    /**
     * Get day of week 1 to 7 for this BigDate according to the ISO standard IS-8601. It is one-based starting with
     * Monday.
     *
     * @return day of week 1=Monday to 7=Sunday, 0 for null date. WARNING: not compatible with 1=Calendar.SUNDAY
     * @see #getCalendarDayOfWeek
     * @see #getDayOfWeek
     * @see #isoDayOfWeek
     */
    public final int getISODayOfWeek()
        {
        return isoDayOfWeek( ordinal );
        }

    /**
     * Get week number 1 to 53 of the year this date falls in, according to the rules of ISO standard IS-8601. A week
     * that lies partly in one year and partly in another is assigned a number in the year in which most of its days
     * lie. This means that week 1 of any year is the week that contains 4 January, or equivalently week 1 of any year
     * is the week that contains the first Thursday in January. Most years have 52 weeks, but years that start on a
     * Thursday and leap years that start on a Wednesday have 53 weeks. Jan 1 may well be in week 53 of the previous
     * year! Only defined for dates on or after 1600 Jan 01. You can find out how many ISO weeks there are per year with
     * new BigDate( year, 12, 31).getISOWeekNumber();
     *
     * @return week number 1..53, 0 for null or invalid date.
     * @see <a href="http://www.pip.dknet.dk/~pip10160/calendar.faq3.txt">Calendar FAQ</a>
     */
    public final int getISOWeekNumber()
        {
        if ( ordinal < Jan_01_Leap100RuleYear )
            {
            return 0;
            }
        int jan04Ordinal = jan01OfYear( yyyy ) + 3;
        int jan04DayOfWeek =
                ( jan04Ordinal + MondayIsZeroAdjustment - MIN_ORDINAL )
                % 7;// 0=Monday
        // 6=Sunday
        int week1StartOrdinal = jan04Ordinal - jan04DayOfWeek;
        if ( ordinal < week1StartOrdinal )
            {// we are part of the previous year. Don't worry about year 0.
            jan04Ordinal = jan01OfYear( yyyy - 1 ) + 3;
            jan04DayOfWeek =
                    ( jan04Ordinal + MondayIsZeroAdjustment - MIN_ORDINAL )
                    % 7;// 0=Monday
            // 6=Sunday
            week1StartOrdinal = jan04Ordinal - jan04DayOfWeek;
            }
        else if ( mm == 12 )
            {// see if we are part of next year. Don't worry about year 0.
            jan04Ordinal = jan01OfYear( yyyy + 1 ) + 3;
            jan04DayOfWeek =
                    ( jan04Ordinal + MondayIsZeroAdjustment - MIN_ORDINAL )
                    % 7;// 0=Monday
            // 6=Sunday
            int week1StartNextOrdinal = jan04Ordinal - jan04DayOfWeek;
            if ( ordinal >= week1StartNextOrdinal )
                {
                week1StartOrdinal = week1StartNextOrdinal;
                }
            }
        return ( ( ordinal - week1StartOrdinal ) / 7 ) + 1;
        }// end getISOWeekNumber

    /**
     * Get java.util.Date object corresponding to this BigDate. We consider this BigDate to have an implied time of 0:00
     * local time.
     *
     * @return Date or null Result is undefined if BigDate is outside the range handled by Date.
     * @see #getLocalTimeStamp
     */
    public final java.util.Date getLocalDate()
        {
        return ordinal == NULL_ORDINAL
               ? null
               : new java.util.Date( getLocalTimeStamp() );
        }

    /**
     * Get milliseconds since 1970 Jan 01 00:00 GMT for this BigDate. Does not account for leap seconds primarily
     * because we do not know them in advance. N.B. returns long, not int as in many Unix implementations. This the long
     * that a Sun Date constructor wants. We consider this BigDate to have an implied time of 0:00 local time.
     *
     * @return milliseconds since 1979 Jan 01 00:00 GMT, or NULL_TIMESTAMP. This is NOT a JDBC Timestamp! You can use
     *         this timestamp with java.util.Date.setTime, java.sql.TimeStamp.setTime or java.sql.Date.setTime or in the
     *         constructors. To interconvert, just cast.
     * @see #getLocalDate
     */
    public final long getLocalTimeStamp()
        {
        return getTimeStamp( TimeZone.getDefault() );
        }

    /**
     * Get month of year for this BigDate.
     *
     * @return month 1 to 12, 0 for null date.
     */
    public final int getMM()
        {
        return mm;
        }

    /**
     * get days since 1970 Jan 01 for this BigDate. 1970/01/01 = day 0.
     *
     * @return days since 1970 Jan 01. This is NOT what you want for the java.util.Date constructor.
     * @see #getLocalTimeStamp
     * @see #getUTCTimeStamp
     * @see #getTimeStamp
     */
    public final int getOrdinal()
        {
        return ordinal;
        }

    /**
     * @return Julian day number of noon of the date BigDate represents. See notes on the Julian Proleptic calendar
     *         under the constructor.
     */
    public final double getProlepticJulianDay()
        {
        if ( ordinal == NULL_ORDINAL )
            {
            return Double.MIN_VALUE;
            }

        return ordinal + 2440588L/* diff in base epochs of calendars */
                /* no need for noon adjust */;
        }// getProlepticJulianDay

    /**
     * Get season of year for this BigDate.
     *
     * @return 0=spring (Mar, Apr, May) 1=summer (Jun, Jul, Aug) 2=fall (Sep, Oct, Dec) 3=winter Dec, Jan, Feb
     */
    public final int getSeason()
        {
        // 1 > 3, 2 > 3, 3 > 0, 4 > 0, 5 > 0, 6 > 1, 7 > 1, 8 > 1, 9 > 2, 10 >
        // 2, 11 > 2, 12 > 3
        return ( ( mm + ( 12 - 3 ) ) % 12 ) / 3;
        }

    /**
     * Get milliseconds since 1970 Jan 01 00:00 GMT for this BigDate, as at the start of day 0:00. Does not account for
     * leap seconds primarily because we do not know them in advance. N.B. returns long, not int as in many Unix
     * implementations. This the long that a Sun Date constructor wants.
     *
     * @param timeZone We consider this BigDate to have an implied time of 0:00 in this timeZone.
     * @return milliseconds since 1979 Jan 01 00:00 GMT, or NULL_TIMESTAMP. This is NOT a JDBC Timestamp! You can use
     *         this timestamp with java.util.Date.setTime, java.sql.TimeStamp.setTime or java.sql.Date.setTime or in the
     *         constructors. To interconvert, just cast.
     * @see #getDate
     * @see #getUTCTimeStamp
     * @see #getLocalTimeStamp
     */
    public final long getTimeStamp( TimeZone timeZone )
        {
        if ( ordinal == NULL_ORDINAL )
            {
            return NULL_TIMESTAMP;
            }
        /*
         * Gets the time zone offset, for current date, modified in case of
         * daylight savings. This is the offset to add *to* UTC to get local
         * time. Places east of Greenwich have a positive offset. :era the era
         * of the given date, AD = 1 BC = 0 :year the year in the given date.
         * Docs are unclear if 1900=0 or 1900. Does not use year in calcs
         * anyway. :month the month in the given date. Month is 0-based. e.g., 0
         * for January. :day the day-in-month of the given date. :dayOfWeek the
         * day-of-week of the given date. 1=Calendar.SUNDAY. :milliseconds the
         * millis in day in <em>standard</em> local time. :return the offset
         * in millis to add *to* GMT to get local time.
         */
        int offsetInMillis =
                timeZone.getOffset( ordinal >= Jan_01_0001 ? 1 : 0,
                        yyyy,
                        mm - 1,
                        dd,
                        getCalendarDayOfWeek(),
                        0 );
        // 86,400,000 = 1000 * 60 * 60 * 24 = milliseconds per day
        return ordinal * 86400000L - offsetInMillis;
        }

    /**
     * Get java.util.Date object corresponding to this BigDate. We consider this BigDate to have an implied time of 0:00
     * UTC (Greenwich GMT).
     *
     * @return Date or null Result is undefined if BigDate is outside the range handled by Date.
     * @see #getUTCTimeStamp
     */
    public final java.util.Date getUTCDate()
        {
        return ordinal == NULL_ORDINAL
               ? null
               : new java.util.Date( getUTCTimeStamp() );
        }

    /**
     * Get milliseconds since 1970 Jan 01 00:00 GMT for this BigDate. Does not account for leap seconds primarily
     * because we do not know them in advance. N.B. returns long, not int as in many Unix implementations. This the long
     * that a Sun Date constructor wants. We consider this BigDate to have an implied time of 0:00 UTC (Greenwich GMT).
     *
     * @return milliseconds since 1970 Jan 01 00:00 GMT, or NULL_TIMESTAMP. This is NOT a JDBC Timestamp! You can use
     *         this timestamp with java.util.Date.setTime, java.sql.TimeStamp.setTime or java.sql.Date.setTime or in the
     *         constructors. To interconvert, just cast.
     * @see #getUTCDate
     */
    public final long getUTCTimeStamp()
        {
        // 86,400,000 = 1000 * 60 * 60 * 24 = milliseconds per day
        return ordinal == NULL_ORDINAL
               ? NULL_TIMESTAMP
               : ( ordinal * 86400000L );
        }

    /**
     * Get week number 1 to 53 of the year this date falls in. This does NOT follow the rules of ISO standard IS-8601
     * section 5.5. Week 1 is the first week with any days in the current year. Weeks start on Sunday. Jan 1 and Dec 31
     * are always considered part of the current year. Only defined for dates on or after 1600 Jan 01.
     *
     * @return week number 1..53, 0 for null or invalid date.
     * @see #getISOWeekNumber
     */
    public final int getWeekNumber()
        {
        if ( ordinal < Jan_01_Leap100RuleYear )
            {
            return 0;
            }
        int jan01 = jan01OfYear( yyyy );
        int jan01DayOfWeek = dayOfWeek( jan01 );// 0=Sunday 1=Monday
        // 2=Tuesday 3=Wednesday
        // 4=Thursday 5=Friday
        // 6=Saturday
        int sundayOnOrBeforeJan01Ordinal = jan01 - jan01DayOfWeek;
        return ( ( ordinal - sundayOnOrBeforeJan01Ordinal ) / 7 ) + 1;
        }// end getWeekNumber

    /**
     * Get year for this BigDate.
     *
     * @return year -999,999 to 999,999. 0 for null date. negative is BC, positive AD.
     */
    public final int getYYYY()
        {
        return yyyy;
        }

    /**
     * hashCode for use in Hashtable lookup
     *
     * @return the ordinal which is perfectly unique for the date.
     */
    public final int hashCode()
        {
        return ordinal;
        }

    /**
     * Find the BigDate with date closest to this one with the given day of week.
     *
     * @param dayOfWeek 0=Sunday 1=Monday 2=Tuesday 3=Wednesday 4=Thursday 5=Friday 6=Saturday WARNING: not compatible
     *                  with 1=Calendar.SUNDAY.
     * @return BigDate object with nearest date to this one with the given day of week.
     */
    public BigDate nearestXXXDay( int dayOfWeek )
        {
        // positive or negative difference -6..0..+6
        int diff = dayOfWeek - this.dayOfWeek();
        if ( diff >= 4 )
            {
            diff -= 7;
            }
        else if ( diff <= -4 )
            {
            diff += 7;
            }
        return new BigDate( this.ordinal + diff );
        }

    /**
     * Set the ordinal field, and compute the equivalent internal Gregorian yyyy mm dd fields. alias setOrdinal.
     *
     * @param ordinal days since 1970 Jan 1.
     */
    public final void set( int ordinal )
        {
        if ( this.ordinal == ordinal )
            {
            return;
            }
        this.ordinal = ordinal;
        toGregorian();
        }// end set

    /**
     * Set the yyyy mm dd Gregorian fields, and compute the internal ordinal equivalent. yyyy mm dd are checked for
     * validity.
     *
     * @param yyyy -999,999 (BC) to +999,999 (AD)
     * @param mm   month 1 to 12 (not 0 to 11 as in Sun's Date), no lead 0.
     * @param dd   day 1 to 31, no lead 0.
     */
    public final void set( int yyyy, int mm, int dd )
        {
        set( yyyy, mm, dd, CHECK );
        }

    /**
     * Set the Gregorian fields, and compute the ordinal equivalent with the same modifiers CHECK, NORMALIZE,
     * BYPASSCHECK as the constructor. BEW