Instant

A java.time.Instant stores information on a particular moment in time.

You can get the current "instant" with Instant.now.

import java.time.Instant;

void main() {
    var now = Instant.now();
    System.out.println(now);
}

But if you happen to know a number milliseconds after January 1, 1970 UTC¹ you can get an Instant which represents that point in time with Instant.ofEpochMilli.

import java.time.Instant;

void main() {
    var january2nd = Instant.ofEpochMilli(86400000);
    System.out.println(january2nd);
}