Meaning of yè jiān:
yè jiān
夜间
Adjective
nighttime
Wǒmen zài yèjiān qù gōngyuán sànbù.
我们在夜间去公园散步。
We go for a walk in the park at nighttime.
Noun
evening or night (e.g. classes)
Wǒ xǐhuān yèjiān de ānjìng.
我喜欢夜间的安静。
I like the tranquility of the night.