Java Calendar Day julianDay(Calendar calendar)

Description

Calculates the julian day of a Calendar .

License

Open Source License

Declaration

public static int julianDay(Calendar calendar) 

Method Source Code

//package com.java2s;
/*//from   ww  w. j  av a2 s.c  o  m
 * (c) Copyright 2007-2013 by Volker Bergmann. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, is permitted under the terms of the
 * GNU General Public License.
 *
 * For redistributing this software or a derivative work under a license other
 * than the GPL-compatible Free Software License as defined by the Free
 * Software Foundation or approved by OSI, you must first obtain a commercial
 * license to this software product from Volker Bergmann.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * WITHOUT A WARRANTY OF ANY KIND. ALL EXPRESS OR IMPLIED CONDITIONS,
 * REPRESENTATIONS AND WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE
 * HEREBY EXCLUDED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Calendar;

import java.util.TimeZone;

public class Main {
    /** Calculates the julian day of a {@link Date}. 
      *  See http://en.wikipedia.org/wiki/Julian_day */
    public static int julianDay(Date date) {
        return julianDay(calendar(date));
    }

    /** Calculates the julian day of a {@link Calendar}. 
      *  See http://en.wikipedia.org/wiki/Julian_day */
    public static int julianDay(Calendar calendar) {
        int year = calendar.get(Calendar.YEAR);
        int month = calendar.get(Calendar.MONTH);
        int day = calendar.get(Calendar.DAY_OF_MONTH);
        return julianDay(year, month + 1, day);
    }

    /** Calculates the julian day of a date. 
      *  See http://en.wikipedia.org/wiki/Julian_day */
    public static int julianDay(int year, int month, int day) {
        int a = (14 - month) / 12;
        int y = year + 4800 - a;
        int m = month + 12 * a - 3;
        int jdn = day + (153 * m + 2) / 5 + 365 * y + y / 4 - y / 100 + y / 400 - 32045;
        return jdn;
    }

    public static Calendar calendar(int year, int month, int day) {
        return new GregorianCalendar(year, month, day);
    }

    public static Calendar calendar(int year, int month, int day, TimeZone timeZone) {
        GregorianCalendar calendar = new GregorianCalendar(timeZone);
        calendar.set(Calendar.YEAR, year);
        calendar.set(Calendar.MONTH, month);
        calendar.set(Calendar.DAY_OF_MONTH, day);
        return calendar;
    }

    public static Calendar calendar(int year, int month, int day, int hours, int minutes, int seconds,
            int milliseconds) {
        GregorianCalendar calendar = new GregorianCalendar(year, month, day, hours, minutes, seconds);
        calendar.set(Calendar.MILLISECOND, milliseconds);
        return calendar;
    }

    public static Calendar calendar(int year, int month, int day, int hours, int minutes, int seconds,
            int milliseconds, TimeZone timeZone) {
        GregorianCalendar calendar = new GregorianCalendar(year, month, day, hours, minutes, seconds);
        calendar.setTimeZone(timeZone);
        calendar.set(Calendar.MILLISECOND, milliseconds);
        return calendar;
    }

    public static Calendar calendar(long millis) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTimeInMillis(millis);
        return calendar;
    }

    public static Calendar calendar(Date date) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        return calendar;
    }
}

Related

1. isToday(Calendar creationDate)
2. isToday(Calendar date)
3. isToday(Calendar now, Calendar then)
4. isTodayOff(String days, Calendar calendar)
5. isWithinDaysFuture(Calendar cal, int days)
6. minOfDay(Calendar calendar)
7. moveToCalendarDay(Calendar cal, int day)
8. moveToCalendarDayJust(Calendar cal)
9. newCalendarForDay(Date date)