java - 如何获取一天的开始时间和结束时间？

Question

如何获取一天的开始时间和结束时间？

像这样的代码不准确：

 private Date getStartOfDay(Date date) {
    Calendar calendar = Calendar.getInstance();
    int year = calendar.get(Calendar.YEAR);
    int month = calendar.get(Calendar.MONTH);
    int day = calendar.get(Calendar.DATE);
    calendar.set(year, month, day, 0, 0, 0);
    return calendar.getTime();
}

private Date getEndOfDay(Date date) {
    Calendar calendar = Calendar.getInstance();
    int year = calendar.get(Calendar.YEAR);
    int month = calendar.get(Calendar.MONTH);
    int day = calendar.get(Calendar.DATE);
    calendar.set(year, month, day, 23, 59, 59);
    return calendar.getTime();
}

它不精确到毫秒。

score 198 · Accepted Answer

爪哇 8

public static Date atStartOfDay(Date date) {
    LocalDateTime localDateTime = dateToLocalDateTime(date);
    LocalDateTime startOfDay = localDateTime.with(LocalTime.MIN);
    return localDateTimeToDate(startOfDay);
}

public static Date atEndOfDay(Date date) {
    LocalDateTime localDateTime = dateToLocalDateTime(date);
    LocalDateTime endOfDay = localDateTime.with(LocalTime.MAX);
    return localDateTimeToDate(endOfDay);
}

private static LocalDateTime dateToLocalDateTime(Date date) {
    return LocalDateTime.ofInstant(date.toInstant(), ZoneId.systemDefault());
}

private static Date localDateTimeToDate(LocalDateTime localDateTime) {
    return Date.from(localDateTime.atZone(ZoneId.systemDefault()).toInstant());
}

更新：我已将这两种方法添加到我的 Java 实用程序类中

它位于 Maven 中央存储库中：

<dependency>
  <groupId>com.github.rkumsher</groupId>
  <artifactId>utils</artifactId>
  <version>1.3</version>
</dependency>

Java 7 及更早版本

使用 Apache Commons

public static Date atEndOfDay(Date date) {
    return DateUtils.addMilliseconds(DateUtils.ceiling(date, Calendar.DATE), -1);
}

public static Date atStartOfDay(Date date) {
    return DateUtils.truncate(date, Calendar.DATE);
}

没有 Apache Commons

public Date atEndOfDay(Date date) {
    Calendar calendar = Calendar.getInstance();
    calendar.setTime(date);
    calendar.set(Calendar.HOUR_OF_DAY, 23);
    calendar.set(Calendar.MINUTE, 59);
    calendar.set(Calendar.SECOND, 59);
    calendar.set(Calendar.MILLISECOND, 999);
    return calendar.getTime();
}

public Date atStartOfDay(Date date) {
    Calendar calendar = Calendar.getInstance();
    calendar.setTime(date);
    calendar.set(Calendar.HOUR_OF_DAY, 0);
    calendar.set(Calendar.MINUTE, 0);
    calendar.set(Calendar.SECOND, 0);
    calendar.set(Calendar.MILLISECOND, 0);
    return calendar.getTime();
}

score 159 · Accepted Answer

159

于 2013-12-12T05:54:12.993 回答

score 29 · Accepted Answer

在 getEndOfDay 中，您可以添加：

calendar.set(Calendar.MILLISECOND, 999);

虽然从数学上讲，你不能指定一天的结束，只能说它是“在第二天开始之前”。

所以不要说if(date >= getStartOfDay(today) && date <= getEndOfDay(today))，，你应该说：if(date >= getStartOfDay(today) && date < getStartOfDay(tomorrow))。这是一个更可靠的定义（您不必担心毫秒精度）。

score 19 · Accepted Answer

java.time

使用java.timeJava 8 内置的框架。

import java.time.LocalTime;
import java.time.LocalDateTime;

LocalDateTime now = LocalDateTime.now(); // 2015-11-19T19:42:19.224
// start of a day
now.with(LocalTime.MIN); // 2015-11-19T00:00
now.with(LocalTime.MIDNIGHT); // 2015-11-19T00:00
// end of a day
now.with(LocalTime.MAX); // 2015-11-19T23:59:59.999999999

score 5 · Accepted Answer

Java 8 或 ThreeTenABP

分区日期时间

ZonedDateTime curDate = ZonedDateTime.now();

public ZonedDateTime startOfDay() {
    return curDate
    .toLocalDate()
    .atStartOfDay()
    .atZone(curDate.getZone())
    .withEarlierOffsetAtOverlap();
}

public ZonedDateTime endOfDay() {

    ZonedDateTime startOfTomorrow =
        curDate
        .toLocalDate()
        .plusDays(1)
        .atStartOfDay()
        .atZone(curDate.getZone())
        .withEarlierOffsetAtOverlap();

    return startOfTomorrow.minusSeconds(1);
}

// based on https://stackoverflow.com/a/29145886/1658268

本地日期时间

LocalDateTime curDate = LocalDateTime.now();

public LocalDateTime startOfDay() {
    return curDate.atStartOfDay();
}

public LocalDateTime endOfDay() {
    return startOfTomorrow.atTime(LocalTime.MAX);  //23:59:59.999999999;
}

// based on https://stackoverflow.com/a/36408726/1658268

我希望这对某人有所帮助。

score 4 · Accepted Answer

使用 java8 java.time.ZonedDateTime 查找一天开始的另一种方法LocalDateTime是简单地将输入 ZonedDateTime 截断为 DAYS：

zonedDateTimeInstance.truncatedTo( ChronoUnit.DAYS );

score 2 · Accepted Answer

另一种不依赖于任何框架的解决方案是：

static public Date getStartOfADay(Date day) {
    final long oneDayInMillis = 24 * 60 * 60 * 1000;
    return new Date(day.getTime() / oneDayInMillis * oneDayInMillis);
}

static public Date getEndOfADay(Date day) {
    final long oneDayInMillis = 24 * 60 * 60 * 1000;
    return new Date((day.getTime() / oneDayInMillis + 1) * oneDayInMillis - 1);
}

请注意，它返回基于 UTC 的时间

score 2 · Accepted Answer

我知道这有点晚了，但在 Java 8 的情况下，如果您使用的是 OffsetDateTime（它提供了很多优势，例如 TimeZone、Nanoseconds 等），您可以使用以下代码：

OffsetDateTime reallyEndOfDay = someDay.withHour(23).withMinute(59).withSecond(59).withNano(999999999);
// output: 2019-01-10T23:59:59.999999999Z

score 2 · Accepted Answer

我试过这段代码，效果很好！

final ZonedDateTime now = ZonedDateTime.now(ZoneOffset.UTC);
final ZonedDateTime startofDay =
    now.toLocalDate().atStartOfDay(ZoneOffset.UTC);
final ZonedDateTime endOfDay =
    now.toLocalDate().atTime(LocalTime.MAX).atZone(ZoneOffset.UTC);

score 2 · Accepted Answer

对于 java 8，以下单行语句正在工作。在此示例中，我使用 UTC 时区。请考虑更改您当前使用的 TimeZone。

System.out.println(new Date());

final LocalDateTime endOfDay       = LocalDateTime.of(LocalDate.now(), LocalTime.MAX);
final Date          endOfDayAsDate = Date.from(endOfDay.toInstant(ZoneOffset.UTC));

System.out.println(endOfDayAsDate);

final LocalDateTime startOfDay       = LocalDateTime.of(LocalDate.now(), LocalTime.MIN);
final Date          startOfDayAsDate = Date.from(startOfDay.toInstant(ZoneOffset.UTC));

System.out.println(startOfDayAsDate);

如果与输出没有时间差。尝试：ZoneOffset.ofHours(0)

score 1 · Accepted Answer

最短的答案，考虑到您的时区是TZ：

LocalDateTime start = LocalDate.now(TZ).atStartOfDay()
LocalDateTime end = start.plusDays(1)

比较使用isAfter()和方法，或使用或方法isBefore()转换它。toEpochSecond()toInstant()

score 1 · Accepted Answer

private Date getStartOfDay(Date date) {
    Calendar calendar = Calendar.getInstance();
    int year = calendar.get(Calendar.YEAR);
    int month = calendar.get(Calendar.MONTH);
    int day = calendar.get(Calendar.DATE);
    calendar.setTimeInMillis(0);
    calendar.set(year, month, day, 0, 0, 0);
    return calendar.getTime();
    }

private Date getEndOfDay(Date date) {
    Calendar calendar = Calendar.getInstance();
    int year = calendar.get(Calendar.YEAR);
    int month = calendar.get(Calendar.MONTH);
    int day = calendar.get(Calendar.DATE);
    calendar.setTimeInMillis(0);
    calendar.set(year, month, day, 23, 59, 59);
    return calendar.getTime();
    }

calendar.setTimeInMillis(0); 为您提供高达毫秒的精度

score 0 · Accepted Answer

我认为最简单的方法是：

// Joda Time

DateTime dateTime=new DateTime(); 

StartOfDayMillis = dateTime.withMillis(System.currentTimeMillis()).withTimeAtStartOfDay().getMillis();
EndOfDayMillis = dateTime.withMillis(StartOfDayMillis).plusDays(1).minusSeconds(1).getMillis();

然后可以根据您的 Joda Time 要求将这些毫秒转换为日历、即时或本地日期。

score 0 · Accepted Answer

 //this will work for user in time zone MST with 7 off set or UTC with saving time 

 //I have tried all the above and they fail the only solution is to use some math
 //the trick is to rely on $newdate is time()     //strtotime is corrupt it tries to read to many minds
 //convert to time to use with javascript*1000
 
 $dnol = strtotime('today')*1000;
 $dn = ($newdate*1000)-86400000;
 $dz=$dn/86400000;      //divide into days
 $dz=floor($dz);     //filter off excess time
 $dzt=$dz*86400000;     // put back into days UTC
 $jsDate=$dzt*1+(7*3600000);     // 7 is the off set you can store the 7 in database
 $dzt=$dzt-3600000;      //adjusment for summerTime UTC additional table for these dates will drive you crazy
 //solution get users [time off sets] with browser, up date to data base for user with ajax when they ain't lookin



 <?php
 $t=time();
 echo($t . "<br>");
 echo(date("Y-m-d",$t));
 echo '<BR>'.$dnol;
 echo '<BR>'.$dzt.'<BR>';
 echo(date("Y-m-d",$dzt/1000));      //convert back for php /1000
 echo '<BR>';
 echo(date('Y-m-d h:i:s',$dzt/1000));

 ?>

score 0 · Accepted Answer

我对所有解决方案都有一些不便，因为我需要Instant变量的类型，而时区总是会干扰更改所有内容，然后结合解决方案我发现这是一个不错的选择。

        LocalDate today = LocalDate.now();
        Instant startDate = Instant.parse(today.toString()+"T00:00:00Z");
        Instant endDate = Instant.parse(today.toString()+"T23:59:59Z");

结果我们有

        startDate = 2020-01-30T00:00:00Z
        endDate = 2020-01-30T23:59:59Z

希望对你有帮助

score 0 · Accepted Answer

以下代码采用 OP 的原始公式，并针对 ms 不精确性进行调整：

    private static Date getStartOfDay() {
        Calendar calendar = Calendar.getInstance();
        int year = calendar.get(Calendar.YEAR);
        int month = calendar.get(Calendar.MONTH);
        int day = calendar.get(Calendar.DATE);
        calendar.set(year, month, day, 0, 0, 0);
        long approximateTimestamp = calendar.getTime().getTime();
        long extraMillis = (approximateTimestamp % 1000);
        long exactTimestamp = approximateTimestamp - extraMillis;
        return new Date(exactTimestamp);
    }

    private static Date getEndOfDay() {
        Calendar calendar = Calendar.getInstance();
        int year = calendar.get(Calendar.YEAR);
        int month = calendar.get(Calendar.MONTH);
        int day = calendar.get(Calendar.DATE);
        calendar.set(year, month, day, 23, 59, 59);
        long approximateTimestamp = calendar.getTime().getTime();
        long extraMillis = (approximateTimestamp % 1000);
        long exactTimestamp = approximateTimestamp - extraMillis + 999;
        return new Date(exactTimestamp);
    }

与此线程上的许多其他答案不同，它与旧版本的 Java 和 Android API 兼容。

score -2 · Accepted Answer

Date date = new Date();
LocalDateTime localDateTime = LocalDateTime.ofInstant(date.toInstant(), ZoneId.systemDefault());
LocalDateTime startOfDay = localDateTime.with(LocalTime.MIN);
LocalDateTime endOfDay = localDateTime.with(LocalTime.MAX);

时间戳：

Timestamp startTs = Timestamp.valueOf(startOfDay);
Timestamp endTs = Timestamp.valueOf(endOfDay);

score -2 · Accepted Answer

public static Date beginOfDay(Date date) {
    Calendar cal = Calendar.getInstance();
    cal.setTime(date);
    cal.set(Calendar.HOUR_OF_DAY, 0);
    cal.set(Calendar.MINUTE, 0);
    cal.set(Calendar.SECOND, 0);
    cal.set(Calendar.MILLISECOND, 0);

    return cal.getTime();
}

public static Date endOfDay(Date date) {
    Calendar cal = Calendar.getInstance();
    cal.setTime(date);
    cal.set(Calendar.HOUR_OF_DAY, 23);
    cal.set(Calendar.MINUTE, 59);
    cal.set(Calendar.SECOND, 59);
    cal.set(Calendar.MILLISECOND, 999);

    return cal.getTime();
}