比较日期以获得经过的日，月，年 [英] Compare Dates to get Elapsed Day,Month,Year

问题描述

我没有什么可以从这里开始，因为我知道的日期比较只是为了看一个日期，如果更小，等于或更大。

我是什么试图实现的是

给定两个日期（包含时间）忽略格式

  2013/11/11 5pm // datetime in mysql 
 2013/11/12 5pm //当前datetime在java代码
  

我如何计算出两个日期之间是否已经过了整整一天？相同的几个月和一年。

是否从新的减去旧的，如果超过24小时，一天过去了。如果超过30天，一个月过去了吗？怎么去呢？

这基本上是检查每日订阅是否每月/每年已过期。

解决方案

24小时≠1天

夏令时（DST）或其他异常可能会影响您的计算是一种日历天可能不要24小时。在美国，我们的DST调整是一个小时，一天可能有23或25小时，而不是24。

所以要明确你的业务逻辑要求：24小时或1天。

当然这都取决于时区。如果在 UTC （没有时区偏移）中工作，一天总是24小时（忽略闰秒） ）

体面日期时间库

与Java捆绑在一起的java.util.Date和.Calendar类是臭名昭着的麻烦。避免他们相反，使用一个体面的日期时间库，其中Java表示：

• Joda-Time


• java.time包（捆绑在Java 8中，灵感来自
  
  

  Joda-时间/rel =nofollow> Joda-Time ，由JSR 310定义）时间

  
  
  

  使用Joda-Time 2.3的一些示例代码。

    String startInput =2013-11-11T17：00Z; 
   String stopInput =2013-11-12T17：00Z; 
   
   DateTimeZone timeZone = DateTimeZone.forID（Europe / Paris）; 
   DateTime start = new DateTime（startInput，timeZone）; 
   DateTime stop = new DateTime（stopInput，timeZone）; 
   
   int daysBetween = Days.daysBetween（start，stop）.getDays（）; 
   int hoursBetween = Hours.hoursBetween（start，stop）.getHours（）; 
    

  转储到控制台...

    System.out.println（start：+ start）; 
   System.out.println（stop：+ stop）; 
   System.out.println（daysBetween：+ daysBetween）; 
   System.out.println（hoursBetween：+ hoursBetween）; 
    

  运行时

   开始：2013-11-11T18：00：00.000 + 01：00 
  停止：2013-11-12T18：00：00.000 + 01：00 
   daysBetween：1 
   hoursBetween：24 
    

  
  

  I dont have anything to start with here since what i know in date comparisons is just to see if a date if lesser, equals or greater.

  what i am trying to achieve is,

  Given two Dates(with time included) ignore the formatting

  2013/11/11 5pm   //datetime in mysql
  2013/11/12 5pm   //current datetime in java code
  

  How can i compute to see if a full day has elapsed between the two dates ? same with months and a year.

  Will it be to subtract the old from the new and if it's greater than 24 hours, a day has elapsed. If it's greater than 30days, a month has elapsed and so on ? how to go about it ?

  This is basically to check if a daily subscription, monthly/yearly has expired.

  解决方案

  24 Hours ≠ 1 Day

  Daylight Saving Time (DST) or other anomalies may affect your calculations is such a way that a calendar "day" may not be 24 hours long. In the United States where our DST adjustment is one hour, a "day" may have 23 or 25 hours instead of 24.

  So be clear on what your business logic demands: 24 hours or 1 day.

  Of course this all depends on time zone. If working in UTC (no time zone offset), a day is always 24 hours (ignoring leap seconds).

  Decent Date-Time Library

  The java.util.Date and .Calendar classes bundled with Java are notoriously troublesome. Avoid them. Instead use a decent date-time library, which in Java means either:

  • Joda-Time
  • java.time package (bundled in Java 8, inspired by Joda-Time, defined by JSR 310)

  Joda-Time

  Some example code using Joda-Time 2.3.

  String startInput = "2013-11-11T17:00Z";
  String stopInput = "2013-11-12T17:00Z";
  
  DateTimeZone timeZone = DateTimeZone.forID( "Europe/Paris" );
  DateTime start = new DateTime( startInput, timeZone );
  DateTime stop = new DateTime( stopInput, timeZone );
  
  int daysBetween = Days.daysBetween( start, stop ).getDays();
  int hoursBetween = Hours.hoursBetween( start, stop ).getHours();
  

  Dump to console…

  System.out.println( "start: " + start );
  System.out.println( "stop: " + stop );
  System.out.println( "daysBetween: " + daysBetween );
  System.out.println( "hoursBetween: " + hoursBetween );
  

  When run…

  start: 2013-11-11T18:00:00.000+01:00
  stop: 2013-11-12T18:00:00.000+01:00
  daysBetween: 1
  hoursBetween: 24
  

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