Statistics are presented with graphs and matrices. The three graphs, first graph at top is all percentiles and quartiles and MAX and MIN, next is reduced to P90 and P10, the bottom graph is scaled to the upper and lower quartile.
Third graph from the top is the one that is most useful, noting the normal range for this month end with the mean and median in the middle of the field. In this post there are matrices that show different values for the calculated period and most importantly win rate, profit factor and avg. trade %, but also index points, sum % and drawdown.
I would say that from trading day -3 (close) until trading day 4 (close) are recommended to go LONG. According to profit factor -3 to 4 has given high return over the years 19.72 in value and high win rate (82%).
Looking at the overall statistics for all, the end of the month so is strongest period between trading -3 to 4. BUY and SELL according to statistics is always done at closing price.