Java Julian Date julianToString(StringBuilder buf, int julian)

Description

julian To String

License

Apache License

Declaration

private static void julianToString(StringBuilder buf, int julian) 

Method Source Code

//package com.java2s;
/*//from w w w .  j av a2  s  .com
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to you under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

public class Main {
    private static void julianToString(StringBuilder buf, int julian) {
        // this shifts the epoch back to astronomical year -4800 instead of the
        // start of the Christian era in year AD 1 of the proleptic Gregorian
        // calendar.
        int j = julian + 32044;
        int g = j / 146097;
        int dg = j % 146097;
        int c = (dg / 36524 + 1) * 3 / 4;
        int dc = dg - c * 36524;
        int b = dc / 1461;
        int db = dc % 1461;
        int a = (db / 365 + 1) * 3 / 4;
        int da = db - a * 365;

        // integer number of full years elapsed since March 1, 4801 BC
        int y = g * 400 + c * 100 + b * 4 + a;
        // integer number of full months elapsed since the last March 1
        int m = (da * 5 + 308) / 153 - 2;
        // number of days elapsed since day 1 of the month
        int d = da - (m + 4) * 153 / 5 + 122;
        int year = y - 4800 + (m + 2) / 12;
        int month = (m + 2) % 12 + 1;
        int day = d + 1;
        int4(buf, year);
        buf.append('-');
        int2(buf, month);
        buf.append('-');
        int2(buf, day);
    }

    private static void int4(StringBuilder buf, int i) {
        buf.append((char) ('0' + (i / 1000) % 10));
        buf.append((char) ('0' + (i / 100) % 10));
        buf.append((char) ('0' + (i / 10) % 10));
        buf.append((char) ('0' + i % 10));
    }

    private static void int2(StringBuilder buf, int i) {
        buf.append((char) ('0' + (i / 10) % 10));
        buf.append((char) ('0' + i % 10));
    }
}

Related

1. julianCentury(double julianDay)
2. julianDate2JDN(int year, int month, int day)
3. julianDay(int day, int month, int year)
4. julianDay(int YY, int MM, int DD)
5. JulianDaysToUnix(double jd)