如何创建今天午夜和明天午夜的Java日期对象?

在我的代码中，我需要找到今天发生的所有事情。因此，我需要将今天凌晨00:00(今天凌晨午夜)到中午12:00(今晚午夜)的日期进行比较。

我知道……

Date today = new Date();

．.．我现在很生气。和…

Date beginning = new Date(0);

…1970年1月1日是零。但是有什么简单的方法可以让你今天和明天的时间都为零呢?

更新

我做到了，但肯定有更简单的方法吧?

Calendar calStart = new GregorianCalendar();
calStart.setTime(new Date());
calStart.set(Calendar.HOUR_OF_DAY, 0);
calStart.set(Calendar.MINUTE, 0);
calStart.set(Calendar.SECOND, 0);
calStart.set(Calendar.MILLISECOND, 0);
Date midnightYesterday = calStart.getTime();
            
Calendar calEnd = new GregorianCalendar();
calEnd.setTime(new Date());
calEnd.set(Calendar.DAY_OF_YEAR, calEnd.get(Calendar.DAY_OF_YEAR)+1);
calEnd.set(Calendar.HOUR_OF_DAY, 0);
calEnd.set(Calendar.MINUTE, 0);
calEnd.set(Calendar.SECOND, 0);
calEnd.set(Calendar.MILLISECOND, 0);
Date midnightTonight = calEnd.getTime();

当前回答

从JodaTime 2.3开始，toDateMidnight()已弃用。

从2.2升级到2.3

    Deprecations since 2.2
    ----------------------
    - DateMidnight [#41]
     This class is flawed in concept
     The time of midnight occasionally does not occur in some time-zones
     This is a result of a daylight savings time from 00:00 to 01:00
     DateMidnight is essentially a DateTime with a time locked to midnight
     Such a concept is more generally a poor one to use, given LocalDate
     Replace DateMidnight with LocalDate
     Or replace it with DateTime, perhaps using the withTimeAtStartOfDay() method

下面是一个没有toDateMidnight()方法的示例代码。

Code

DateTime todayAtMidnight = new DateTime().withTimeAtStartOfDay();
System.out.println(todayAtMidnight.toString("yyyy-MM-dd HH:mm:ss"));

输出(根据您所在的时区可能有所不同)

2013-09-28 00:00:00

2013-09-27 10:44:34

其他回答

java.time

如果您使用的是Java 8及以上版本，您可以尝试Java。时间包(教程):

LocalDate tomorrow = LocalDate.now().plusDays(1);
Date endDate = Date.from(tomorrow.atStartOfDay(ZoneId.systemDefault()).toInstant());

2015-08-10 12:19:13

JDK8 - Java时间模块方式:

LocalDateTime todayMidnight = LocalDate.now（）.atStartOfDay（）;

也工作:

LocalDateTime todayMidnight = LocalDateTime.now（）.with（LocalTime.MIDNIGHT）;

2020-12-13 15:27:56

因为一天是24 * 60 * 60 * 1000毫秒，这一天的午夜可以计算为……

long now = System.currentTimeMillis();
long delta = now % 24 * 60 * 60 * 1000;
long midnight = now - delta;
Date midnightDate = new Date(midnight);`

2016-10-31 03:04:52

从JodaTime 2.3开始，toDateMidnight()已弃用。

从2.2升级到2.3

    Deprecations since 2.2
    ----------------------
    - DateMidnight [#41]
     This class is flawed in concept
     The time of midnight occasionally does not occur in some time-zones
     This is a result of a daylight savings time from 00:00 to 01:00
     DateMidnight is essentially a DateTime with a time locked to midnight
     Such a concept is more generally a poor one to use, given LocalDate
     Replace DateMidnight with LocalDate
     Or replace it with DateTime, perhaps using the withTimeAtStartOfDay() method

下面是一个没有toDateMidnight()方法的示例代码。

Code

DateTime todayAtMidnight = new DateTime().withTimeAtStartOfDay();
System.out.println(todayAtMidnight.toString("yyyy-MM-dd HH:mm:ss"));

输出(根据您所在的时区可能有所不同)

2013-09-28 00:00:00

2013-09-27 10:44:34

这似乎是一个选项:

DateFormat justDay = new SimpleDateFormat("yyyyMMdd");
Date thisMorningMidnight = justDay.parse(justDay.format(new Date()));

也可以再加一天

Date tomorrow = new Date(thisMorningMidnight.getTime() + 24 * 60 * 60 * 1000);

Calendar c = Calendar.getInstance();
c.setTime(thisMorningMidnight);
c.add(Calendar.DATE, 1);
Date tomorrowFromCalendar = c.getTime();

我有一种预感，后者是首选，以防一些奇怪的事情，如夏令时，导致增加24小时不够(见https://stackoverflow.com/a/4336131/32453及其其他答案)。

2014-08-18 19:46:40

如何创建今天午夜和明天午夜的Java日期对象?

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