Time-position adverbials typically serve as responses to ‘when’ questions:
1a. 你是什么时候到北京的?
Nǐ shi shenme shihou dao Běijīng de ?
(When did you arrive in Beijing?)
1b. 昨天晚上/最近/五点钟/你开会的时候。
Zuotiān wǎnshang/Zuijin/Wǔ diǎnzhōng/Nǐ kāihui shihou.
(Last night/Recently/At five o’clock/When you were having the meeting.)
Commonly used time-position adverbials that denote a point or a period of time include: those denoted by NPs, such as 三点‘sāndiǎn’ (three o’clock), 当今‘dāngjīn’ (nowadays, present time); and those denoted by adverbs, like 早 ‘zǎo’ (early, at an early time), 晚‘wǎn’ (late, at a late time), 先‘xiān’ (before all else, first), 接着‘jiēzhe’ (next, immediately after), etc.
[1] Loar, J. K. (2011). Chinese syntactic grammar: functional and conceptual principles. New York: Peter Lang.