during summer vacation
夏休みの間に私は多くの村人と親しくなった。
I got to know many villagers during the summer vacation.
あなたは夏休みの間に何をするつもりですか。
What are you planning to do during summer vacation?
夏休みの間にそれをした。
I did that during summer vacation.
彼女は夏休みの間に髪型を変えた。
She changed her hairstyle during the summer vacation.