您可以尝试较早版本的Java。

 public static String daysBetween(Date createdDate, Date expiryDate) {

        Calendar createdDateCal = Calendar.getInstance();
        createdDateCal.clear();
        createdDateCal.setTime(createdDate);

        Calendar expiryDateCal = Calendar.getInstance();
        expiryDateCal.clear();
        expiryDateCal.setTime(expiryDate);


        long daysBetween = 0;
        while (createdDateCal.before(expiryDateCal)) {
            createdDateCal.add(Calendar.DAY_OF_MONTH, 1);
            daysBetween++;
        }
        return daysBetween+"";
    }

这可能是最直接的方法了——也许是因为我已经用Java编写了一段时间了(它的日期和时间库确实很笨拙)，但对我来说，代码看起来“简单而漂亮”!

您是否对以毫秒为单位返回的结果感到满意，或者您的问题的一部分是希望以某种替代格式返回?

注意:startDate和endDates为-> java.util.Date

import org.joda.time.Duration;
import org.joda.time.Interval;
// Use .getTime() unless it is a joda DateTime object
Interval interval = new Interval(startDate.getTime(), endDate.getTime());
Duration period = interval.toDuration();
//gives the number of days elapsed between start and end date.
period.getStandardDays();

与天类似，你也可以得到小时、分钟和秒

period.getStandardHours();
period.getStandardMinutes();
period.getStandardSeconds();

您可以尝试较早版本的Java。

 public static String daysBetween(Date createdDate, Date expiryDate) {

        Calendar createdDateCal = Calendar.getInstance();
        createdDateCal.clear();
        createdDateCal.setTime(createdDate);

        Calendar expiryDateCal = Calendar.getInstance();
        expiryDateCal.clear();
        expiryDateCal.setTime(expiryDate);


        long daysBetween = 0;
        while (createdDateCal.before(expiryDateCal)) {
            createdDateCal.add(Calendar.DAY_OF_MONTH, 1);
            daysBetween++;
        }
        return daysBetween+"";
    }

你需要更清楚地定义你的问题。您可以只取两个Date对象之间的毫秒数，然后除以24小时内的毫秒数，例如……但是:

这将不考虑时区-日期总是UTC 这并没有考虑到日光节约时间(例如，有些日子可能只有23小时) 即使在UTC时间内，8月16日晚上11点到8月18日凌晨2点有多少天?只有27个小时，那意味着一天吗?还是应该是三天，因为它涵盖了三个日期?

查看示例http://www.roseindia.net/java/beginners/DateDifferent.shtml 这个例子给出了天、小时、分钟、秒和毫秒的差异:)。

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

public class DateDifferent {
    public static void main(String[] args) {
        Date date1 = new Date(2009, 01, 10);
        Date date2 = new Date(2009, 07, 01);
        Calendar calendar1 = Calendar.getInstance();
        Calendar calendar2 = Calendar.getInstance();
        calendar1.setTime(date1);
        calendar2.setTime(date2);
        long milliseconds1 = calendar1.getTimeInMillis();
        long milliseconds2 = calendar2.getTimeInMillis();
        long diff = milliseconds2 - milliseconds1;
        long diffSeconds = diff / 1000;
        long diffMinutes = diff / (60 * 1000);
        long diffHours = diff / (60 * 60 * 1000);
        long diffDays = diff / (24 * 60 * 60 * 1000);
        System.out.println("\nThe Date Different Example");
        System.out.println("Time in milliseconds: " + diff + " milliseconds.");
        System.out.println("Time in seconds: " + diffSeconds + " seconds.");
        System.out.println("Time in minutes: " + diffMinutes + " minutes.");
        System.out.println("Time in hours: " + diffHours + " hours.");
        System.out.println("Time in days: " + diffDays + " days.");
    }
}