>looking at August seasonals
Pirates were 2021
The Theieves' Masque was 2022
Invitation to Tea was 2023
Yukata Festival was last year as of 2024. Prior was 2018.

>looking at September seasonals
Dance festival was 2020
Scion of the Twelve was 2021
Tribal Festival has been active since 2022 so it's likely another Tribal banner.

Hot Spring (January) and Spring Picnic (April) debuted in the same year of 2019 and have been retired in favor of Desert Festival and World of Origin.