Date Time in Java

    Java LocalDate class is an immutable class that represents Date with a default format of yyyy-mm-dd. It inherits Object class and implements the ChronoLocalDate interface.

import java.time.LocalDate;

public class Main {

    public static void main(String[] args) {

        // Creating a LocalDate object representing today's date

        LocalDate today = LocalDate.now();

        System.out.println("Today's date: " + today);

        // Creating a LocalDate object for a specific date

        LocalDate specificDate = LocalDate.of(2024, 4, 23);

        System.out.println("Specific date: " + specificDate);

        // Getting components of a LocalDate

        int year = specificDate.getYear();

        int month = specificDate.getMonthValue();

        int day = specificDate.getDayOfMonth();

        System.out.println("Year: " + year + ", Month: " + month + ", Day: " + day);

        // Manipulating LocalDate objects

        LocalDate futureDate = specificDate.plusDays(7); // Adding 7 days

        System.out.println("Date 7 days from now: " + futureDate);

        LocalDate pastDate = specificDate.minusMonths(3); // Subtracting 3 months

        System.out.println("Date 3 months ago: " + pastDate);

        // Comparing LocalDate objects

        LocalDate anotherDate = LocalDate.of(2024, 5, 15);

        if (specificDate.isBefore(anotherDate)) {

            System.out.println(specificDate + " is before " + anotherDate);

        } else {

            System.out.println(specificDate + " is after " + anotherDate);

        }

    }

}

Java LocalTime class is an immutable class that represents time with a default format of hour-minute-second. It inherits Object class and implements the Comparable interface.

import java.time.LocalTime;

public class Main {

    public static void main(String[] args) {

        // Creating a LocalTime object representing the current time

        LocalTime currentTime = LocalTime.now();

        System.out.println("Current time: " + currentTime);

        // Creating a LocalTime object for a specific time

        LocalTime specificTime = LocalTime.of(14, 30, 45); // hour, minute, second

        System.out.println("Specific time: " + specificTime);

        // Getting components of a LocalTime

        int hour = specificTime.getHour();

        int minute = specificTime.getMinute();

        int second = specificTime.getSecond();

        int nano = specificTime.getNano(); // fraction of second

        System.out.println("Hour: " + hour + ", Minute: " + minute + ", Second: " + second + ", Nano: " + nano);

        // Manipulating LocalTime objects

        LocalTime futureTime = specificTime.plusHours(2); // Adding 2 hours

        System.out.println("Time 2 hours from now: " + futureTime);

        LocalTime pastTime = specificTime.minusMinutes(15); // Subtracting 15 minutes

        System.out.println("Time 15 minutes ago: " + pastTime);

        // Comparing LocalTime objects

        LocalTime anotherTime = LocalTime.of(10, 0, 0);

        if (specificTime.isBefore(anotherTime)) {

            System.out.println(specificTime + " is before " + anotherTime);

        } else {

            System.out.println(specificTime + " is after " + anotherTime);

        }

    }

}

Java LocalDateTime class is an immutable date-time object that represents a date-time, with the default format as yyyy-MM-dd HH-mm-ss.zzz. It inherits object class and implements the ChronoLocalDateTime interface.

import java.time.LocalDateTime;

public class Main {

    public static void main(String[] args) {

        // Creating a LocalDateTime object representing the current date and time

        LocalDateTime currentDateTime = LocalDateTime.now();

        System.out.println("Current date and time: " + currentDateTime);

        // Creating a LocalDateTime object for a specific date and time

        LocalDateTime specificDateTime = LocalDateTime.of(2024, 4, 23, 14, 30, 45); // year, month, day, hour, minute, second

        System.out.println("Specific date and time: " + specificDateTime);

        // Getting components of a LocalDateTime

        int year = specificDateTime.getYear();

        int month = specificDateTime.getMonthValue();

        int day = specificDateTime.getDayOfMonth();

        int hour = specificDateTime.getHour();

        int minute = specificDateTime.getMinute();

        int second = specificDateTime.getSecond();

        System.out.println("Year: " + year + ", Month: " + month + ", Day: " + day +

                           ", Hour: " + hour + ", Minute: " + minute + ", Second: " + second);

        // Manipulating LocalDateTime objects

        LocalDateTime futureDateTime = specificDateTime.plusDays(7); // Adding 7 days

        System.out.println("Date and time 7 days from now: " + futureDateTime);

        LocalDateTime pastDateTime = specificDateTime.minusMonths(3); // Subtracting 3 months

        System.out.println("Date and time 3 months ago: " + pastDateTime);

        // Comparing LocalDateTime objects

        LocalDateTime anotherDateTime = LocalDateTime.of(2024, 5, 15, 10, 0, 0);

        if (specificDateTime.isBefore(anotherDateTime)) {

            System.out.println(specificDateTime + " is before " + anotherDateTime);

        } else {

            System.out.println(specificDateTime + " is after " + anotherDateTime);

        }

    }

}

Java Period class is used to measures time in years, months and days. It inherits the Object class and implements the ChronoPeriod interface.

import java.time.LocalDate;

import java.time.Period;

public class Main {

    public static void main(String[] args) {

        // Creating LocalDate objects for two dates

        LocalDate startDate = LocalDate.of(2020, 1, 1);

        LocalDate endDate = LocalDate.of(2024, 4, 23);

        // Calculating the period between the two dates

        Period period = Period.between(startDate, endDate);

        // Accessing the components of the period

        int years = period.getYears();

        int months = period.getMonths();

        int days = period.getDays();

        System.out.println("Period between " + startDate + " and " + endDate + ":");

        System.out.println("Years: " + years);

        System.out.println("Months: " + months);

        System.out.println("Days: " + days);

        // Creating a Period using of() method

        Period additionalPeriod = Period.of(1, 2, 3); // 1 year, 2 months, and 3 days

        // Printing the additionalPeriod

        System.out.println("Additional Period: " + additionalPeriod); // Additional Period: P1Y2M3D

    }

}

Java Duration class is used to measures time in seconds and nanoseconds. It inherits the Object class and implements the Comparable interface.

import java.time.Duration;

import java.time.LocalTime;

public class Main {

    public static void main(String[] args) {

        // Creating LocalTime objects for two times

        LocalTime startTime = LocalTime.of(10, 30, 0);

        LocalTime endTime = LocalTime.of(12, 45, 30);

        // Calculating the duration between the two times

        Duration duration = Duration.between(startTime, endTime);

        // Accessing the components of the duration

        long seconds = duration.getSeconds();

        long nano = duration.getNano();

        System.out.println("Duration between " + startTime + " and " + endTime + ":");

        System.out.println("Seconds: " + seconds);

        System.out.println("Nanoseconds: " + nano);

        // Manipulating a LocalTime using a Duration

        LocalTime newTime = startTime.plus(duration);

        System.out.println("New time after adding the duration: " + newTime);

    }

}