zero hour (noun) zero hour: moment of truth
Sinonime: A-day, D-day, D-day, H-hour, appointed hour, appointed hour,
climax,
contingency, countdown,
crisis, crisis point, crossroad, crossroads, crunch time,
deadline,
emergency,
exigency, jumping-off point,
juncture, moment of truth,
pinch, pivotal moment, start time, strait,
target, target day, the time,
turning point, turning point*, vital moment