Comparing two Instant objects can be accomplished via the Instant.isAfter() and Instant.isBefore() methods. For example, let's look at the following two Instant objects:
Instant timestamp1 = Instant.now();
Instant timestamp2 = timestamp1.plusSeconds(10);
Check whether timestamp1 is after timestamp2:
boolean isAfter = timestamp1.isAfter(timestamp2); // false
Check whether timestamp1 is before timestamp2:
boolean isBefore = timestamp1.isBefore(timestamp2); // true
The time difference between two Instant objects can be computed via the Instant.until() method:
// 10 seconds
long difference = timestamp1.until(timestamp2, ChronoUnit.SECONDS);