zero hour

英文解釋：

名詞 zero hour:

1. the time set for the start of an action or operation

例句：

1. Get your equipment ready, it's coming up to zero hour.
   把你們的器材準備好，開始行動的時刻到了。
2. On the day of the championship game, as the zero hour came near, the players grew nervous.
   決賽的那天，比賽將開始時，選手們顯得十分緊張。