/** Subtract a relative time from this time and return the new instant in time. */
public Abstime subtract(Reltime relTime) {
return new Abstime(millis - relTime.getMillis(), timeZone);
}
/** Add a relative time to this time and return the new instant in time. */
public Abstime add(Reltime relTime) {
return new Abstime(millis + relTime.getMillis(), timeZone);
}