Calculate the number of days between start and end. - Java java.util

Java examples for java.util:Day

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Description

Calculate the number of days between start and end.

Demo Code

/******************************************************************************
 * Product: Adempiere ERP & CRM Smart Business Solution                       *
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//package com.java2s;
import java.sql.Timestamp;

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

public class Main {
    /**//w  w  w.java 2  s . c  o m
     *    Calculate the number of days between start and end.
     *    @param start start date
     *    @param end end date
     *    @return number of days (0 = same)
     */
    static public int getDaysBetween(Timestamp start, Timestamp end) {
        boolean negative = false;
        if (end.before(start)) {
            negative = true;
            Timestamp temp = start;
            start = end;
            end = temp;
        }
        //
        GregorianCalendar cal = new GregorianCalendar();
        cal.setTime(start);
        cal.set(Calendar.HOUR_OF_DAY, 0);
        cal.set(Calendar.MINUTE, 0);
        cal.set(Calendar.SECOND, 0);
        cal.set(Calendar.MILLISECOND, 0);
        GregorianCalendar calEnd = new GregorianCalendar();
        calEnd.setTime(end);
        calEnd.set(Calendar.HOUR_OF_DAY, 0);
        calEnd.set(Calendar.MINUTE, 0);
        calEnd.set(Calendar.SECOND, 0);
        calEnd.set(Calendar.MILLISECOND, 0);

        //   System.out.println("Start=" + start + ", End=" + end + ", dayStart=" + cal.get(Calendar.DAY_OF_YEAR) + ", dayEnd=" + calEnd.get(Calendar.DAY_OF_YEAR));

        //   in same year
        if (cal.get(Calendar.YEAR) == calEnd.get(Calendar.YEAR)) {
            if (negative)
                return (calEnd.get(Calendar.DAY_OF_YEAR) - cal
                        .get(Calendar.DAY_OF_YEAR)) * -1;
            return calEnd.get(Calendar.DAY_OF_YEAR)
                    - cal.get(Calendar.DAY_OF_YEAR);
        }

        //   not very efficient, but correct
        int counter = 0;
        while (calEnd.after(cal)) {
            cal.add(Calendar.DAY_OF_YEAR, 1);
            counter++;
        }
        if (negative)
            return counter * -1;
        return counter;
    }
}

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