Jidaimono refers to the Kabuki and Kyogen (farce played during a Noh play cycle) by Ningyo joruri (traditional Japanese puppet theater), which depict the world before the Sengoku period (period of warring states).
歌舞伎や人形浄瑠璃の狂言で、戦国時代(日本)以前の世界を描いた作品。