At two hours fifty-six Greenwich Mean Time on July twentieth,nineteen sixty-nine, Neil Armstrong put his foot on the moon.

VOA: special.2009.07.15

the reason being that's where Greenwich Mean Time is.

原因是那里就是格林威治的标准时间所在之处。

时间开始的地方 - SpeakingMax英语口语达人

That is Greenwich Mean Time.

那就是格林威治标准时间。

时间开始的地方 - SpeakingMax英语口语达人