Title here
Summary here
A common requirement in programs is getting the number of seconds, milliseconds, or nanoseconds since the Unix epoch. Here’s how to do it in Java.
import java.time.Instant;
public class Epoch {
public static void main(String[] args) {
// Use Instant.now() to get the current time
Instant now = Instant.now();
System.out.println(now);
// Get elapsed time since the Unix epoch in seconds,
// milliseconds or nanoseconds
System.out.println(now.getEpochSecond());
System.out.println(now.toEpochMilli());
System.out.println(now.getNano());
// You can also convert integer seconds or nanoseconds
// since the epoch into the corresponding Instant
System.out.println(Instant.ofEpochSecond(now.getEpochSecond()));
System.out.println(Instant.ofEpochSecond(0, now.getNano()));
}
}
To run the program:
$ javac Epoch.java
$ java Epoch
2023-05-11T12:34:56.789012Z
1683808496
1683808496789
789012000
2023-05-11T12:34:56Z
1970-01-01T00:00:00.789012Z
Next, we’ll look at another time-related task: time parsing and formatting.