Nobody knows exactly how many years it will be--Chinese football team enters the final stage of the

Nobody knows exactly how many years it will be before Chinese football team enters the final stage of the World Cup.
谁也说不清中国足球队要进入世界杯需要多少年.
Abefore “在……之前”,表示在中国足球队进入世界杯（之前）需要多少年
Buntil“指导……时”,表示需要多少年中国足球队才能进入世界而杯但有什么具体区别呀？