How do I get the nearest hour, minute, second of a date?

This example demonstrate how to use the DateUtils.round() method to get the nearest hour, minute and second of a date.

package org.kodejava.example.commons.lang;

import org.apache.commons.lang3.time.DateFormatUtils;
import org.apache.commons.lang3.time.DateUtils;
import org.apache.commons.lang3.time.FastDateFormat;

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

public class DateRoundingDemo {
    public static void main(String[] args) {
        FastDateFormat formatter = DateFormatUtils.ISO_8601_EXTENDED_DATETIME_TIME_ZONE_FORMAT;

        Date now = new Date();
        System.out.println("now = " + formatter.format(now));

        // Get nearest second
        Date nearestSecond = DateUtils.round(now, Calendar.SECOND);
        System.out.println("nearestSecond = " + formatter.format(nearestSecond));

        // Get nearest minute
        Date nearestMinute = DateUtils.round(now, Calendar.MINUTE);
        System.out.println("nearestMinute = " + formatter.format(nearestMinute));

        // Get nearest hour
        Date nearestHour = DateUtils.round(now, Calendar.HOUR);
        System.out.println("nearestHour = " + formatter.format(nearestHour));
    }
}

Here are the program results:

now = 2019-07-24T10:29:21+08:00
nearestSecond = 2019-07-24T10:29:22+08:00
nearestMinute = 2019-07-24T10:29:00+08:00
nearestHour = 2019-07-24T10:00:00+08:00

Maven Dependencies

<!-- https://search.maven.org/remotecontent?filepath=org/apache/commons/commons-lang3/3.9/commons-lang3-3.9.jar -->
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.9</version>
</dependency>

Maven Central

How do I format date and time using DateFormatUtils class?

The DateFormatUtils class help us to format date and time information. This class use an instance of org.apache.commons.lang.time.FastDateFormat class to format the date and time information. Compared to Java SimpleDateFormat, the FastDateFormat class is thread safe.

If you want to create a custom date format you can use the FastDateFormat class directly.

package org.kodejava.example.commons.lang;

import org.apache.commons.lang3.time.DateFormatUtils;

import java.util.Date;

public class DateFormattingDemo {
    public static void main(String[] args) {
        Date today = new Date();

        // ISO8601 formatter for date-time without time zone.
        // The format used is yyyy-MM-dd'T'HH:mm:ss.
        String timestamp = DateFormatUtils.ISO_8601_EXTENDED_DATETIME_FORMAT.format(today);
        System.out.println("timestamp = " + timestamp);

        // ISO8601 formatter for date-time with time zone.
        // The format used is yyyy-MM-dd'T'HH:mm:ssZZ.
        timestamp = DateFormatUtils.ISO_8601_EXTENDED_DATETIME_TIME_ZONE_FORMAT.format(today);
        System.out.println("timestamp = " + timestamp);

        // The format used is EEE, dd MMM yyyy HH:mm: ss Z in US locale.
        timestamp = DateFormatUtils.SMTP_DATETIME_FORMAT.format(today);
        System.out.println("timestamp = " + timestamp);
    }
}

The result of the code snippet:

timestamp = 2019-07-24T10:17:12
timestamp = 2019-07-24T10:17:12+08:00
timestamp = Wed, 24 Jul 2019 10:17:12 +0800

Maven Dependencies

<!-- https://search.maven.org/remotecontent?filepath=org/apache/commons/commons-lang3/3.9/commons-lang3-3.9.jar -->
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.9</version>
</dependency>

Maven Central