FULL PRODUCT VERSION :
java version "1.8.0_60"
Java(TM) SE Runtime Environment (build 1.8.0_60-b27)
Java HotSpot(TM) 64-Bit Server VM (build 25.60-b23, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
OS X 10.11.5 El Capitan

A DESCRIPTION OF THE PROBLEM :
For dates before 1582, Timestamp.from(...) and toInstant() are consistently off by a few days.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the following program:

import java.sql.Timestamp;
import java.time.Instant;

public class Time {
  public static void main(String[] args) {
    Instant i = Instant.parse("1582-01-01T00:00:00Z");
    Timestamp t = Timestamp.valueOf("1582-01-01 00:00:00");

    System.out.println(t.toInstant());
    System.out.println(Timestamp.from(i));
  }
}

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Should return 1582-01-01T00:00:00Z
ACTUAL -
Returns offset dates.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.sql.Timestamp;
import java.time.Instant;

public class Time {
  public static void main(String[] args) {
    Instant i = Instant.parse("1582-01-01T00:00:00Z");
    Timestamp t = Timestamp.valueOf("1582-01-01 00:00:00");

    System.out.println(t.toInstant());
    System.out.println(Timestamp.from(i));
  }
}
---------- END SOURCE ----------