EP 12 MAJOR SPOILERS: When?

You get a good zoom of Lu Guang's watch and the wall clock.

S2E12 The watch shows
???? 09 13 (blurred out year)
00:05
20 seconds
The clock shows ~12:05 13sec (consistent with the watch reading of 00:05)

I looked back at S1E1, the clock shows ~11:57 5sec. The watch shows 2021 04 16 21:57 09sec. Clearly, the scene from S2E12 occurred at a different date than the scene from S1E1. More likely, it is around the time of S2E1.

(S2E1, time immediately after stabbing is around 05:51 08sec. Watch says 05:52, date is illegible)
(S2E1, when Xiaoshi is in jail there is a flash to the clock showing 02:40 52 sec. I don't know the date.)