As applied to the [[Six Orbits of Time]], systole refers to the midpoint of the Orbit, exactly one half of the Orbit. In time-keeping, systole refers to one-half of the measure of its Orbit. As applied to Time and to the [[Six Orbits of Time]], diastole refers to the coincident beginning and end points of the Orbit. In time-keeping, diastole refers to the start of the measure of its Orbit.