Time Period
A date-based amount of time can be represented with the
Period type. With this data type a time span is expressed
as a number of years, months and days.
Since Java 8
import java.time.LocalDate;
import java.time.Period;
import java.time.ZoneId;
public class HowOldIsJava {
static final LocalDate BIRTHDAY_OF_JAVA = LocalDate.of(1995, 5, 23);
static final ZoneId TIMEZONE_OF_BIRTH = ZoneId.of("America/Los_Angeles");
public static void main(String[] args) {
var today = LocalDate.now(TIMEZONE_OF_BIRTH);
var age = Period.between(BIRTHDAY_OF_JAVA, today);
System.out.println("As of today Java is %s old".formatted(fmt(age)));
var nextAnivesary = BIRTHDAY_OF_JAVA.plus(Period.ofYears(age.getYears() + 1));
var tillAnivesary = Period.between(today, nextAnivesary);
System.out.println("Java's next birthday is in %s".formatted(fmt(tillAnivesary)));
}
static String fmt(Period p) {
// Unfortunately there is no built-in formatter for Period objects
return "%d years, %d months and %d days".formatted(p.getYears(), p.getMonths(), p.getDays());
}
}
This snippet at GitHub