This is the 5784th most frequent Turkish word.
sezonunu
The Turkish word "sezonunu" means "its season" or "the season of."
The word "sezonunu" here refers to "the season of" (kış - winter), indicating a specific season.
Kış sezonunu seviyoruz.
We love the winter season.
The word "sezonunu" is used here to denote a distinct time of operational change for the restaurant (yazlık - summer).
Bu restoran yazlık sezonunu başlamış.
This restaurant has started its summer season.
In this sentence, "sezonunu" means "the season of" (yeni - new) a series, designating a particular set of episodes.