A timing window refers to a period that is dense with participants sharing a common motivation. Characteristics of that common motivation can be observed in the patterns that develop during the window, which are then predictive of future price action (e.g. direction, targets, ranges, aggression).
Commonly motivated participants enact their bullish or bearish opinion, and push price up or down to the degree that represents the strength of their opinions, relative to participants that are expressing an opposing opinion. Behaviors and patterns can be a breakout or a failed test, messy choppiness or narrow ranging, neutralizing an outstanding objective or creating a new one. These efforts and others reflect intention (or lack of intent!) that then informs our own confidence in a specific outlook.