With the new Date and Time APIs provided in Java 8, adding and subtracting date time have never been easier. Here are some examples using LocalDateTime.

package net.openwritings.java.time;
 
import java.time.LocalDateTime;
import java.time.temporal.ChronoUnit;
 
public class AddSubDateTime {
 
    public static void main(String[] args) {
 
        // Get today date time.
        LocalDateTime today = LocalDateTime.now();
        System.out.println("today = " + today.toString());
 
        // Additions.
        System.out.println(" 2 seconds later = " + today.plusSeconds(2).toString());
        System.out.println(" 3 mintues later = " + today.plusMinutes(3).toString());
        System.out.println(" 5 hours   later = " + today.plusHours(5).toString());
        System.out.println(" 7 days    later = " + today.plusDays(7).toString());
        System.out.println(" 5 weeks   later = " + today.plusWeeks(5).toString());
        System.out.println(" 9 months  later = " + today.plusMonths(9).toString());
        System.out.println("10 years   later = " + today.plusYears(10).toString());
 
        // Subtractions.
        System.out.println(" 2 seconds ago = " + today.minusSeconds(2).toString());
        System.out.println(" 3 mintues ago = " + today.minusMinutes(3).toString());
        System.out.println(" 5 hours   ago = " + today.minusHours(5).toString());
        System.out.println(" 7 days    ago = " + today.minusDays(7).toString());
        System.out.println(" 5 weeks   ago = " + today.minusWeeks(5).toString());
        System.out.println(" 9 months  ago = " + today.minusMonths(9).toString());
        System.out.println("10 years   ago = " + today.minusYears(10).toString());
 
        // Get the different between 2 dates.
        LocalDateTime tomorrow = today.plusDays(1);
        long minutes = ChronoUnit.MINUTES.between(today, tomorrow);
        System.out.println("Number of minutes between today & tomorrow is: " + minutes);
    }
 
}

Output

today = 2019-06-15T18:14:16.425
 2 seconds later = 2019-06-15T18:14:18.425
 3 mintues later = 2019-06-15T18:17:16.425
 5 hours   later = 2019-06-15T23:14:16.425
 7 days    later = 2019-06-22T18:14:16.425
 5 weeks   later = 2019-07-20T18:14:16.425
 9 months  later = 2020-03-15T18:14:16.425
10 years   later = 2029-06-15T18:14:16.425
 2 seconds ago = 2019-06-15T18:14:14.425
 3 mintues ago = 2019-06-15T18:11:16.425
 5 hours   ago = 2019-06-15T13:14:16.425
 7 days    ago = 2019-06-08T18:14:16.425
 5 weeks   ago = 2019-05-11T18:14:16.425
 9 months  ago = 2018-09-15T18:14:16.425
10 years   ago = 2009-06-15T18:14:16.425
Number of minutes between today & tomorrow is: 1440

Github

https://github.com/xuanngo2001/java-small/blob/master/src/net/openwritings/java/time/AddSubDateTime.java

Java, Java 8

About the author

Xuan Ngo is the founder of OpenWritings.net. He currently lives in Montreal, Canada. He loves to write about programming and open source subjects.

Java - Add / Subtract date time

Output

Github

About the author