现在是北京时间十六点，可以说成 "It is four o'clock in Beijing."。
来源："o'clock" 是 "of the clock" 的缩写，意思是"钟点"。所以 "four o'clock" 就是 "四点钟"。
英文例句：
I will meet you at four o'clock in Beijing. (我会在北京的四点钟见你)
The fpght to Beijing leaves at four o'clock. (飞往北京的航班在四点钟起飞)
中文翻译：
我会在北京的四点钟见你。
飞往北京的航班在四点钟起飞。