csUnchanDs3ConfigTimeElapsed is a read-only counter of the seconds elapsed since the start of the current 15-minute near-end error-measurement period on this DS3 interface, capped at the maximum value if the system clock jumps. Admins use it to normalize the error counts in the current interval, since a handful of errors 30 seconds into the window is far more alarming than the same count after 800 seconds. For example, seeing five Errored Seconds when csUnchanDs3ConfigTimeElapsed reads only 60 tells an admin the interface is degrading fast, whereas the same five errors at 890 seconds is a comparatively quiet interval.