This integer, ranging 1 to 900 seconds, reports how much of the current 15-minute Section-layer error-measurement period has elapsed so far, including partial seconds. An admin cares because it lets them judge how much weight to give the current-interval Section error counters — a value near 900 means the interval is nearly complete and its counts are close to final, while a low value means the counters are still accumulating. For example, a value of 45 alongside a spike in cwSonetSectionCurrentESs signals a fast-developing burst of errors within just the first minute of this interval.