zero hour

名词 zero hour:

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

1. Get your equipment ready, it's coming up to zero hour.
   把你们的器材准备好，开始行动的时刻到了。
2. On the day of the championship game, as the zero hour came near, the players grew nervous.
   决赛的那天，比赛将开始时，选手们显得十分紧张。