Mega Code Archive
Convert dates to Julian dates
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//-----------------------------------------------------------------------------
// JulianDateConverter.java
//
// (c) 2004 Jonathan Stott
//
// Created on 13-Apr-2004
//
// 0.1 - 13 Apr 2004
// Initial Version
//-----------------------------------------------------------------------------
//package uk.me.jstott.util;
import java.util.Calendar;
/**
* Convert dates to Julian dates.
*
* For more information on using this class, look at
* http://www.jstott.me.uk/jsuntimes/
*
* @author Jonathan Stott
* @version 0.1
*/
class JulianDateConverter {
/**
* Convert a date/time to a Julian date
*
* @param date the date the convert
* @return the Julian date
*/
public static double dateToJulian(Calendar date) {
int year = date.get(Calendar.YEAR);
int month = date.get(Calendar.MONTH)+1;
int day = date.get(Calendar.DAY_OF_MONTH);
int hour = date.get(Calendar.HOUR_OF_DAY);
int minute = date.get(Calendar.MINUTE);
int second = date.get(Calendar.SECOND);
double extra = (100.0 * year) + month - 190002.5;
return (367.0 * year) -
(Math.floor(7.0 * (year + Math.floor((month + 9.0) / 12.0)) / 4.0)) +
Math.floor((275.0 * month) / 9.0) +
day + ((hour + ((minute + (second / 60.0)) / 60.0)) / 24.0) +
1721013.5 - ((0.5 * extra) / Math.abs(extra)) + 0.5;
}
}
]]>