TSN airport suffers from heavy fog during cold temp especially in winter and in the morning.D7 flights into TSN usually arrive early in the morning.D7 have several times delayed the TSN flight so that they arrived a bit later.plus sometimes flight arriving to TSN have been diverted PEK.this affects the rest of the scheduling.D7 have a tight flt scheduling so delays or diversion in one of the flights means it will affect other D7 flights.
Rescheduling the TSN flights means it'll affect other D7 flights.