context: Today, I'm going on an airplane trip, so last night I packed my suitcase. I thought carefully about everything I would need on my trip. How many changes of clothing would I need? Would I need to bring things like toothpaste, and my toothbrush? I looked through my closet and picked the clothing that I decided to bring with me. I brought my shirts, my pants, my underwear, and my socks. I brought enough for a week's worth of clothes, which is how long I'm going to be staying somewhere else. Then, I went into the bathroom and got my toothbrush and a tube of my toothpaste, so I wouldn't have to get new ones where I'm going. Finally, I decided to pack a few books with me, in case I needed something to do while I was at my hotel. Then, I closed up my suitcase, and was ready to go on my trip.
question: When did they pack the suitcase?
reference: The night before the flight.
candidate: night before summer .