How to add hours, minutes, seconds into DateTime in Joda-Time?

In this example you will learn how to add hours, minutes or seconds to a DateTime object in Joda-Time. Some methods are available to add or subtract hours, minutes or seconds from the object, as you can see in the example below.

The DateTime object is an immutable object, which means calling one of the plus() or minus() method does not modified the current object. Instead, these methods return a new DateTime object for each method calls.

In the code snippet below we call the plus() and minus() method without storing the result of the operation, we are only going to print it out. The get the new value of the DateTime object you need to assign it to a variable.

package org.kodejava.example.joda;

import org.joda.time.DateTime;

public class TimeCalculationDemo {
    public static void main(String[] args) {
        // Creates an instance of current DateTime which represents the
        // current date time.
        DateTime dateTime = new DateTime();
        System.out.println("DateTime            = " + dateTime);

        // Plus some hours, minutes, and seconds to the original DateTime.
        System.out.println("Plus 60 seconds is  = " + dateTime.plusSeconds(60));
        System.out.println("Plus 10 minutes is  = " + dateTime.plusMinutes(10));
        System.out.println("Plus 1 hour is      = " + dateTime.plusHours(1));

        // Minus some hours, minutes, and seconds to the original DateTime.
        System.out.println("Minus 60 seconds is = " + dateTime.minusSeconds(60));
        System.out.println("Minus 10 minutes is = " + dateTime.minusMinutes(10));
        System.out.println("Minus 1 hour is     = " + dateTime.minusHours(1));
    }
}

The program print the following result. The output shows the result of adding or subtracting seconds, minutes and hours the the DateTime object.

DateTime            = 2017-01-15T09:29:20.621+08:00
Plus 60 seconds is  = 2017-01-15T09:30:20.621+08:00
Plus 10 minutes is  = 2017-01-15T09:39:20.621+08:00
Plus 1 hour is      = 2017-01-15T10:29:20.621+08:00
Minus 60 seconds is = 2017-01-15T09:28:20.621+08:00
Minus 10 minutes is = 2017-01-15T09:19:20.621+08:00
Minus 1 hour is     = 2017-01-15T08:29:20.621+08:00

How do I format date in Joda-Time using ISODateTimeFormat class?

This example demonstrate how to use the ISODateTimeFormat class to format the date time information in Joda-Time.

package org.kodejava.example.joda;

import org.joda.time.DateTime;
import org.joda.time.format.ISODateTimeFormat;

public class ISODateTimeFormatDemo {
    public static void main(String[] args) {
        DateTime dateTime = DateTime.now();

        // Returns a basic formatter for a full date as four digit
        // year, two digit month of year, and two digit day of
        // month yyyyMMdd.
        System.out.println(dateTime.toString(
                ISODateTimeFormat.basicDate()));
        System.out.println(dateTime.toString(
                ISODateTimeFormat.basicDateTime()));
        System.out.println(dateTime.toString(
                ISODateTimeFormat.basicDateTimeNoMillis()));

        // Returns a formatter for a full ordinal date, using a four
        // digit year and three digit dayOfYear yyyyDDD.
        System.out.println(dateTime.toString(
                ISODateTimeFormat.basicOrdinalDate()));

        // Returns a basic formatter for a full date as four digit
        // weekyear, two digit week of weekyear, and one digit day
        // of week xxxx'W'wwe
        System.out.println(dateTime.toString(
                ISODateTimeFormat.basicWeekDate()));
        System.out.println(dateTime.toString(
                ISODateTimeFormat.basicWeekDateTime()));
    }
}

The result of the code above is printed below:

20170116
20170116T233404.650+0800
20170116T233404+0800
2017016
2017W031
2017W031T233404.650+0800

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

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. An interval object represent an interval of time from one millisecond instant to another 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());

        // 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);
    }
}

Below is the result printed by our program:

Interval = 2017-01-16T23:28:49.324/2017-03-16T23:28:49.324
Start    = 2017-01-16T23:28:49.324+08:00
End      = 2017-03-16T23:28:49.324+08:00
Interval = 2017-01-16T23:28:49.324/2017-04-16T23:28:49.324
Duration = PT7776000S

How do I get number of days between two dates in Joda-Time?

The following code snippet show you how to get days between two dates. You can use the Days.daysBetween() method and pass the dates you want to calculate. This method return a Days object. To get the number in days you call the getDays() method.

package org.kodejava.example.joda;

import org.joda.time.DateMidnight;
import org.joda.time.Days;
import org.joda.time.LocalDate;
import org.joda.time.Months;

public class DaysBetweenDemo {
    public static void main(String[] args) {
        // Define the start and end dates. We use the DateMidnight
        // class to make sure that the calculation start from the
        // midnight.
        DateMidnight start = new DateMidnight("2017-01-01");
        DateMidnight end = new DateMidnight("2017-01-16");

        // Get days between the start date and end date.
        int days = Days.daysBetween(start, end).getDays();

        // Print the result.
        System.out.println("Days between " +
                start.toString("yyyy-MM-dd") + " and " +
                end.toString("yyyy-MM-dd") + " = " +
                days + " day(s)");

        // Using LocalDate object.
        LocalDate date1 = LocalDate.parse("2017-01-01");
        LocalDate date2 = LocalDate.now();
        days = Days.daysBetween(date1, date2).getDays();

        // Print the result.
        System.out.println("Days between " +
                date1.toString("yyyy-MM-dd") + " and " +
                date2.toString("yyyy-MM-dd") + " = " +
                days + " day(s)");

    }
}

Here is the result of the program:

Days between 2017-01-01 and 2017-01-16 = 15 day(s)
Days between 2017-01-01 and 2017-01-16 = 15 day(s)

How do I get number of months between two dates in Joda-Time?

The code below show you how to use the Months class to calculate the different in months between two dates.

package org.kodejava.example.joda;

import org.joda.time.DateMidnight;
import org.joda.time.LocalDate;
import org.joda.time.Months;

import java.util.Date;

public class MonthsBetweenDemo {
    public static void main(String[] args) {
        // Creates an instance of start and end dates.
        DateMidnight start = new DateMidnight("2016-06-01");
        DateMidnight end = new DateMidnight(new Date());

        // Get months between these dates.
        int months = Months.monthsBetween(start, end).getMonths();

        // Print the result.
        System.out.println("Months between " +
                start.toString("yyyy-MM-dd") + " and " +
                end.toString("yyyy-MM-dd") + " = " +
                months + " month(s)");

        // Using LocalDate object.
        LocalDate date1 = LocalDate.parse("2016-03-25");
        LocalDate date2 = LocalDate.now();
        months = Months.monthsBetween(date1, date2).getMonths();

        // Print the result.
        System.out.println("Months between " +
                date1.toString("yyyy-MM-dd") + " and " +
                date2.toString("yyyy-MM-dd") + " = " +
                months + " month(s)");
    }
}

Here is the output of our program:

Months between 2016-06-01 and 2017-01-16 = 7 month(s)
Months between 2016-03-25 and 2017-01-16 = 9 month(s)

How do I convert Joda-Time’s DateTime into Calendar or Date object?

This code snippet show you how to convert Joda-Time’s DateTime object into JDK’s java.util.Calendar or java.util.Date object. To convert DateTime to java.util.Date we use the toDate() method and to convert to java.util.Calendar we use the toCalendar() method.

package org.kodejava.example.joda;

import org.joda.time.DateTime;

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

public class DateTimeToDateCalendarDemo {
    public static void main(String[] args) {
        // Converting DateTime object into JDK's Date.
        DateTime dateTime = DateTime.now();
        Date date = dateTime.toDate();
        System.out.println("dateTime = " + dateTime);
        System.out.println("date     = " + date);

        // Converting DateTime object into JDK's Calendar.
        Calendar calendar = dateTime.toCalendar(Locale.getDefault());
        System.out.println("calendar = " + calendar);
    }
}

The result of our code snippet:

dateTime = 2017-01-16T14:06:22.332+08:00
date     = Mon Jan 16 14:06:22 WITA 2017
calendar = java.util.GregorianCalendar[time=1484546782332,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="Asia/Makassar",offset=28800000,dstSavings=0,useDaylight=false,transitions=5,lastRule=null],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2017,MONTH=0,WEEK_OF_YEAR=3,WEEK_OF_MONTH=3,DAY_OF_MONTH=16,DAY_OF_YEAR=16,DAY_OF_WEEK=2,DAY_OF_WEEK_IN_MONTH=3,AM_PM=1,HOUR=2,HOUR_OF_DAY=14,MINUTE=6,SECOND=22,MILLISECOND=332,ZONE_OFFSET=28800000,DST_OFFSET=0]

How do I do a date calculations in Joda-Time?

Using the Joda-Time library can simplify the date calculation process. For instance we can add or subtract some days, weeks, months or year easily. There are a plus and minus method for this operation. For instance if you want to add 9 weeks to date object you can do something like date.plusWeeks(9).

package org.kodejava.example.joda;

import org.joda.time.LocalDate;

public class DateCalculationDemo {
    public static void main(String[] args) {
        // Creates an instance of LocalDate where we are going to do
        // some date calculations.
        LocalDate date = new LocalDate(2017, 1, 1);
        System.out.println("Date           = " + date);

        // Add days, weeks, months, year value into the date object.
        System.out.println("plusDays(10)   = " + date.plusDays(10));
        System.out.println("plusWeeks(9)   = " + date.plusWeeks(9));
        System.out.println("plusMonths(2)  = " + date.plusMonths(2));
        System.out.println("plusYears(1)   = " + date.plusYears(1));

        // Subtract days, weeks, months, year value from date object.
        System.out.println("minusDays(10)  = " + date.minusDays(10));
        System.out.println("minusWeeks(9)  = " + date.minusWeeks(9));
        System.out.println("minusMonths(2) = " + date.minusMonths(2));
        System.out.println("minusYears(1)  = " + date.minusYears(1));
    }
}

The output of the program above are:

Date           = 2017-01-01
plusDays(10)   = 2017-01-11
plusWeeks(9)   = 2017-03-05
plusMonths(2)  = 2017-03-01
plusYears(1)   = 2018-01-01
minusDays(10)  = 2016-12-22
minusWeeks(9)  = 2016-10-30
minusMonths(2) = 2016-11-01
minusYears(1)  = 2016-01-01

How do I format DateTime object in Joda-Time?

The example show you how to format the string representation of a date. In Joda we can use the DateTime‘s class toString() method. The method accept the pattern of the date format and the locale information.

package org.kodejava.example.joda;

import org.joda.time.DateTime;
import org.joda.time.format.DateTimeFormat;

import java.util.Locale;

public class FormattingDemo {
    // Define the date format pattern.
    private static final String pattern = "E MM/dd/yyyy HH:mm:ss.SSS";

    public static void main(String[] args) {
        // Creates a new instance of DateTime object.
        DateTime dt = DateTime.now();

        // Print out the date as a formatted string using the defined
        // Locale information.
        System.out.println("Pattern  = " + pattern);
        System.out.println("Default  = " + dt.toString(pattern));
        System.out.println("Germany  = " + dt.toString(pattern, Locale.GERMANY));
        System.out.println("French   = " + dt.toString(pattern, Locale.FRENCH));
        System.out.println("Japanese = " + dt.toString(pattern, Locale.JAPANESE));

        // Using predefined format from DateTimeFormat class.
        System.out.println("fullDate   = " + dt.toString(DateTimeFormat.fullDate()));
        System.out.println("longDate   = " + dt.toString(DateTimeFormat.longDate()));
        System.out.println("mediumDate = " + dt.toString(DateTimeFormat.mediumDate()));
        System.out.println("shortDate  = " + dt.toString(DateTimeFormat.shortDate()));
        System.out.println("dd/MM/yyyy = " + dt.toString(DateTimeFormat.forPattern("dd/MM/yyyy")));
    }
}

Here an the example result of our program:

Pattern  = E MM/dd/yyyy HH:mm:ss.SSS
Default  = Mon 01/16/2017 10:53:32.939
Germany  = Mo 01/16/2017 10:53:32.939
French   = lun. 01/16/2017 10:53:32.939
Japanese = 月 01/16/2017 10:53:32.939
fullDate   = Monday, January 16, 2017
longDate   = January 16, 2017
mediumDate = Jan 16, 2017
shortDate  = 1/16/17
dd/MM/yyyy = 16/01/2017

How do I get date and time fields of DateTime object in Joda-Time?

In Joda-Time the date and time information are divided into fields. The following example show you some fields that can be obtained from the DateTime object. For example to get the day of the year we use the getDayOfYear() method and to get the day of week we can use the getDayOfWeek() method.

package org.kodejava.example.joda;

import org.joda.time.DateTime;

public class DateTimeFieldDemo {
    public static void main(String[] args) {
        DateTime dateTime = new DateTime();
        System.out.println("dateTime = " + dateTime);

        // Get day of year, day of month, day of week and week of
        // year of a date.
        System.out.println("DOY = " + dateTime.getDayOfYear());
        System.out.println("DOM = " + dateTime.getDayOfMonth());
        System.out.println("DOW = " + dateTime.getDayOfWeek());
        System.out.println("WOW = " + dateTime.getWeekOfWeekyear());

        // Get hour of day, minute of hour and second of minute.
        System.out.println("HOD = " + dateTime.getHourOfDay());
        System.out.println("MOH = " + dateTime.getMinuteOfHour());
        System.out.println("SOM = " + dateTime.getSecondOfMinute());

        // Get minute of day and second of day.
        System.out.println("MOD = " + dateTime.getMinuteOfDay());
        System.out.println("SOD = " + dateTime.getSecondOfDay());
    }
}

The outputs of our program are:

dateTime = 2017-01-16T09:43:36.662+08:00
DOY = 16
DOM = 16
DOW = 1
WOW = 3
HOD = 9
MOH = 43
SOM = 36
MOD = 583
SOD = 35016