How do I use Joda-Time’s Instant Class?

An instant in the datetime continuum specified as a number of milliseconds from 1970-01-01T00:00Z. Some classes that represent an instance in the Joda-Time library includes the Instant, DateTime, DateMidnight and MutableDateTime classes.

package org.kodejava.example.joda;

import org.joda.time.DateTime;
import org.joda.time.Instant;

public class InstantDemo {
    public static void main(String[] args) {
        // An instant in the datetime continuum specified as
        // a number of milliseconds from 1970-01-01T00:00Z.
        //
        // The declaration below creates 1 seconds instant from
        // 1970.
        Instant instant = new Instant(1000);

        // Get a new copy of instant with 500 duration added.
        instant = instant.plus(500);

        // Get a new copy of instant with 250 duration taken away.
        instant = instant.minus(250);
        System.out.println("Milliseconds = " + instant.getMillis());

        // Creating an instant that represent the current date.
        DateTime dateTime = new DateTime();
        System.out.println("Date Time = " + dateTime);

        // Creating an instant of a specific date and time.
        DateTime independenceDay = new DateTime(2017, 8, 17, 0, 0, 0);
        System.out.println("Independence Day = " + independenceDay);
    }
}

Here is the result of our program:

Milliseconds = 1250
Date Time = 2017-01-16T23:32:15.070+08:00
Independence Day = 2017-08-17T00:00:00.000+08:00

Maven Dependencies

<!-- http://repo1.maven.org/maven2/joda-time/joda-time/2.9.7/joda-time-2.9.7.jar -->
<dependency>
    <groupId>joda-time</groupId>
    <artifactId>joda-time</artifactId>
    <version>2.9.7</version>
</dependency>

How do I use the Interval class of Joda-Time?

This example show you how to use the org.joda.time.Interval class in Joda-Time. A time interval represents a period of time between two instants. Intervals are inclusive of the start instant and exclusive of the end. The end instant is always greater than or equal to the start instant.

package org.kodejava.example.joda;

import org.joda.time.DateTime;
import org.joda.time.Duration;
import org.joda.time.Interval;
import org.joda.time.Months;

public class IntervalDemo {
    public static void main(String[] args) {
        DateTime startDate = new DateTime();
        DateTime endDate = startDate.plus(Months.months(2));

        // Creates an interval from a start to an end instant.
        Interval interval = new Interval(startDate, endDate);
        System.out.println("Interval = " + interval);
        System.out.println("Start    = " + interval.getStart());
        System.out.println("End      = " + interval.getEnd());

        System.out.println("Days     = " + interval.toDuration().getStandardDays());
        System.out.println("Hours    = " + interval.toDuration().getStandardHours());
        System.out.println("Minutes  = " + interval.toDuration().getStandardMinutes());
        System.out.println("Seconds  = " + interval.toDuration().getStandardSeconds());

        // Add one more month to the interval
        interval = interval.withEnd(interval.getEnd().plusMonths(1));
        System.out.println("Interval = " + interval);

        // Gets the duration of this time interval
        Duration duration = interval.toDuration();
        System.out.println("Duration = " + duration);
        System.out.println("Days     = " + duration.getStandardDays());
        System.out.println("Hours    = " + duration.getStandardHours());
        System.out.println("Minutes  = " + duration.getStandardMinutes());
        System.out.println("Seconds  = " + duration.getStandardSeconds());
    }
}

Below is the result printed by our program:

Interval = 2017-02-16T15:37:19.746+08:00/2017-04-16T15:37:19.746+08:00
Start    = 2017-02-16T15:37:19.746+08:00
End      = 2017-04-16T15:37:19.746+08:00
Days     = 59
Hours    = 1416
Minutes  = 84960
Seconds  = 5097600
Interval = 2017-02-16T15:37:19.746+08:00/2017-05-16T15:37:19.746+08:00
Duration = PT7689600S
Days     = 89
Hours    = 2136
Minutes  = 128160
Seconds  = 7689600

Maven Dependencies

<!-- http://repo1.maven.org/maven2/joda-time/joda-time/2.9.7/joda-time-2.9.7.jar -->
<dependency>
    <groupId>joda-time</groupId>
    <artifactId>joda-time</artifactId>
    <version>2.9.7</version>
</dependency>