(Pro 7:9 KJV) In the twilight, in the evening, in the black and dark night:
For most of us the times listed in this verse are our times of most vulnerability. We are tired and unfocused. If there is a part of the day when we are least attentive, these qualify. This is when the young man in question is moving toward tragedy. He is moving step by step. He has plenty of opportunity to change or withdraw, but onward he goes.
So? Most of our great sins were seen a long way off. They are the ones that are harder to have forgiven because they were not moments of weakness but the result of planning and choice. The time to avoid sin is when it first occurs to us.