The intermediate term advance from the MAR lows lasted 68 days into JUN 17; since then the SPX/DOW have turned nicely at 1.382 (7/23 exact low), 1.500 (8/6 exact low), and 1.618 (8/19 closing high) Fibonacci trading day time intervals.
MAR 13+ (2*68) trading days=Sep 22=Fall Equinox. It will be interesting to see if broader averages continue to march to this natural rhythm.