public static NanoClock systemDefaultZone() {
		return DEFAULT_INSTANCE;
	}
This clock is based on the <i>nano</i> system clock. It uses
{@link System#nanoTime()} resolution
<p>
Conversion from instant to date or time uses the specified time-zone.
<p>
The returned implementation is immutable, thread-safe and
{@code Serializable}.

@return a clock that uses the best available system clock in the
        default zone
@throws java.lang.NullPointerException if the given {@code zone} is
        {@code null}
jenetics/src/main/java/io/jenetics/util/NanoClock.java