For reference since I get confused
Chap 1 to half of 30: present
Half 30 to half 44: school days
Half 44 to 85: present
86 to 108: the girl's memories
109 to 121: present
122 to half 123: archery thing school days
Half 123 to 133: present
134 to 144: memories of the dude
145 to half 147: present
Half 147 to 174: about half of THE past
175 to 183: present
184 to 209: THE past part 2
209 to 259; the end
260 onwards: extras?
Mo Dao Zu Shi