If today, 5/21, is day [0] then yesterday, 5/20, is day [1] and the day before yesterday, 5/19, is day [2].
Ok, day 2 had a range of 24 and it was a "down" day. So we extend that expansion off of the low of day 2 to see if day 1 will break through by 1 tick or more. Day 1 did just that...