Instant and Duration
Machine time and intervals.
Machine Time
While LocalDateTime is for human calendars, Instant represents a precise point on the machine timeline, measured from the epoch of 1970-01-01 in UTC.
Duration represents a length of time between two instants.
Creating an Instant
Instant.now() captures the current moment. For predictable output we can build one from a fixed epoch second with ofEpochSecond.
import java.time.Instant;
public class Main {
public static void main(String[] args) {
Instant fixed = Instant.ofEpochSecond(1000000000);
System.out.println(fixed);
}
}