Timeline

=== 2021 04 14 ===
===== Emma’s late night shift (taken over) =====
 Time: 22:00
 Source: Ep.1
=== 2021 04 15 ===
===== Emma’s kidnapping and death =====
 Time: 05:52
 Source: S1 and S2 Ep. 1
=== 2021 04 16 ===
===== First "link" we observe. =====
 Time: 22:00 to 10:00 the next day
 Source: Ep.1 4:50
=== 2021 10 13 ===
===== Find the whereabouts of the kid who got kidnapped (CCTV) =====
 Time: 14:30
 Source: Ep.6 19:11
===== Event: Find the whereabouts of the kid who got kidnapped (Kid POV) =====
 Time: Unknown, between 14:40 - 15:00
 Ep.7 14:45
 Note: Saw Qiao Ling around 3 years ago in the summer of 2018.
=== 2021 10 18 ===
===== Xu Shanshan’s Karaoke =====
 Time: Night (Unknown) into the morning
 Source: Ep. 8
 Note: See note on 10/21
=== 2021 10 20 ===
===== Xu Shanshan comes for a request. =====
 Time: 10:05
 Source: Ep. 8
===== Xu Shanshan takes a selfie with Qiao Ling =====
 Time: 16:00
 Source: Ep.10 9:55
 
=== 2021 10 21 (Thursday) ===
===== Attack on Xu Shanshan =====
 Time: 01:30
 Source: Ep.10 7:02
===== Crew found out Xu Shanshan has not been responsive =====
 Time: 09:56
 Source: Ep.8 21:19
 Note: Xu shan shan said the karaoke was at night the day before yesterday. Assuming Cheng Xiaoshi and Lu Guang linked immediately today, this places the request date on 10/20, and the karaoke night on 10/18.
=== 2021 10 22 ===
===== Killer arrives at the photo house =====
 Time: 1:24
 Source: Ep.10 18:56
===== Killer gets trapped inside the photo room =====
 Time: 01:30
 Source: Ep.10 20:22
===== Attempt to save Emma (Cheng Xiaoshi) =====
 Time: 03:53 - 03:55
 Source: Ep.11 14:04
===== Qiao Ling stabs Lu Guang =====
 Time: 5:51
 Source: S2 Ep.1 05:13
===== Liu Min (controlled) strangles himself =====
 Time: 5:52
 Source: S2 Ep.1 06:12 (unless the scenes are not played in chronological order)