Java Age Calculate calculateAgeInMonth(final Date birthDate, final Date asOfDate)

Description

Calculate age based on the birth date and the reference date.

License

Open Source License

Parameter

Parameter	Description
birthDate	the birth date
asOfDate	the reference date to calculate the age

Return

the age in month

Declaration

private static int calculateAgeInMonth(final Date birthDate,
        final Date asOfDate) 

Method Source Code

//package com.java2s;
/**//from   w w w  . j a va 2s.co m
 * The contents of this file are subject to the OpenMRS Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://license.openmrs.org
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations
 * under the License.
 *
 * Copyright (C) OpenMRS, LLC.  All Rights Reserved.
 */

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

public class Main {
    /**
     * Calculate age based on the birth date and the reference date. The returned age is in month. The remaining days will be rounded to the closest one
     * month value.
     *
     * @param birthDate the birth date
     * @param asOfDate  the reference date to calculate the age
     * @return the age in month
     */
    private static int calculateAgeInMonth(final Date birthDate,
            final Date asOfDate) {

        Calendar birthCalendar = Calendar.getInstance();
        birthCalendar.setTime(birthDate);

        Calendar todayCalendar = Calendar.getInstance();
        todayCalendar.setTime(asOfDate);

        int birthYear = birthCalendar.get(Calendar.YEAR);
        int todayYear = todayCalendar.get(Calendar.YEAR);

        int ageInYear = todayYear - birthYear;

        int birthMonth = birthCalendar.get(Calendar.MONTH);
        int todayMonth = todayCalendar.get(Calendar.MONTH);

        int ageInMonth = todayMonth - birthMonth;
        if (ageInMonth < 0) {
            ageInYear--;
            ageInMonth = 12 - birthMonth + todayMonth;
        }

        int birthDay = birthCalendar.get(Calendar.DATE);
        int todayDay = todayCalendar.get(Calendar.DATE);

        int ageInDay = todayDay - birthDay;
        if (ageInDay < 0) {
            ageInMonth--;

            // we need to calculate the age in day using previous month
            Calendar calendar = GregorianCalendar.getInstance();
            calendar.set(Calendar.MONTH, todayMonth - 1);

            birthCalendar.add(Calendar.MONTH, -1);
            ageInDay = calendar.getActualMaximum(Calendar.DATE) - birthDay
                    + todayDay;
        }

        if (ageInDay > todayCalendar.getActualMaximum(Calendar.DATE) / 2)
            ageInMonth++;

        ageInMonth = ageInMonth + (ageInYear * 12);
        return ageInMonth;
    }
}

Related

1. calculateAge(Date birthDate)
2. calculateAge(Date birthday)
3. calculateAge(Date dateOfBirth)
4. calculateAge(Date dob)
5. calculateAge(Date DOB)
6. calculateAgeInWeek(final Date birthDate, final Date asOfDate)
7. getAge(Date birthDate, Date controlDate)
8. getAge(Date birthDay)
9. getAge(Date birthday)