package in.bench.resources.java8.offsetdatetime.examples;

import java.time.Duration;
import java.time.OffsetDateTime;
import java.time.Period;
import java.time.ZoneOffset;

public class FindDifferenceOfTwoOffsetDateTime {

	public static void main(String[] args) {

		// get default Offset
		ZoneOffset zoneOffset = ZoneOffset.of("+05:30");
		System.out.println("Default system zone is :- \n" + zoneOffset);


		// 1. organization joining date
		OffsetDateTime joiningDateTime = OffsetDateTime
				.of(2017, 3, 6, 10, 32, 56, 123456789, zoneOffset);
		System.out.println("\nOrganization Joining Date/time is :- \n" + joiningDateTime);


		// 2. organization relieving date
		OffsetDateTime relievingDateTime = OffsetDateTime
				.of(2019, 6, 28, 20, 31, 43, 987654321, zoneOffset);
		System.out.println("\nOrganization Relieving Date/time is :- \n" + relievingDateTime);


		// 3. difference between 2 LocalDate - Days spent in a organization
		Period period = Period.between(
				joiningDateTime.toLocalDate(), 
				relievingDateTime.toLocalDate()
				);
		System.out.println("\nPeriod between 2 LocalDate is :- \n" + period);


		// 3.1 get difference of years/months/days
		int years = period.getYears();
		int months = period.getMonths();
		int days = period.getDays();


		// 4. difference between 2 LocalTime - Time duration spent in Office
		Duration duration = Duration.between(
				joiningDateTime.toLocalTime(), 
				relievingDateTime.toLocalTime()
				);
		System.out.println("\nTime Duration between 2 LocalTime is :- \n" + duration);


		// 4.1 get difference in nanos/seconds
		int nanos = duration.getNano(); 
		long seconds = duration.getSeconds();


		// 5. print to console
		System.out.print("\nPeriod & Time Duration spent in an Organization is :- \n"
				+ years + " Years " 
				+ months + " Months " 
				+ days + " Days "
				+ seconds + " Seconds "
				+ nanos + " Nanos");
	}
}

Default system zone is :- 
+05:30

Organization Joining Date/time is :- 
2017-03-06T10:32:56.123456789+05:30

Organization Relieving Date/time is :- 
2019-06-28T20:31:43.987654321+05:30

Period between 2 LocalDate is :- 
P2Y3M22D

Time Duration between 2 LocalTime is :- 
PT9H58M47.864197532S

Period & Time Duration spent in an Organization is :- 
2 Years 3 Months 22 Days 35927 Seconds 864197532 Nanos

package in.bench.resources.java8.offsetdatetime.examples;

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

public class FindDifferenceOfTwoCalendarDateTime {

	public static void main(String[] args) {

		// 1. organization joining date - Instantiate GregorianCalendar
		Calendar calendar1 = new GregorianCalendar(2017, 2, 6, 10, 32, 56); // March
		Date date1 = calendar1.getTime();
		System.out.println("Organization Joining Date/time is :- \n" + date1);


		// 2. organization relieving date - Instantiate GregorianCalendar
		Calendar calendar2 = new GregorianCalendar(2019, 5, 28, 20, 31, 43); // June
		Date date2 = calendar2.getTime();
		System.out.println("\nOrganization Relieving Date/time is :- \n" + date2);


		// 3. difference between 2 Date/time - Days spent in a organization
		long differenceInMillis = date2.getTime() - date1.getTime();


		// 3.1 get difference of years/days/hours/minutes/seconds
		long years = (differenceInMillis / (365 * 24 * 60 * 60 * 1000L)); 
		long days = (differenceInMillis / (24 * 60 * 60 * 1000L)) % 365;
		long hours = (differenceInMillis / (60 * 60 * 1000L)) % 24;
		long minutes = (differenceInMillis / (60 * 1000L)) % 60;
		long seconds = (differenceInMillis / 1000) % 60;   


		// 3.2 print to console
		System.out.print("\nTime Duration spent in an Office is :- \n"
				+ years + " Years " 
				+ days + " Days "
				+ hours + " Hours " 
				+ minutes + " Minutes "
				+ seconds + " Seconds"
				);
	}
}

Organization Joining Date/time is :- 
Mon Mar 06 10:32:56 IST 2017

Organization Relieving Date/time is :- 
Fri Jun 28 20:31:43 IST 2019

Time Duration spent in an Office is :- 
2 Years 114 Days 9 Hours 58 Minutes 47 Seconds