dear candidate,

as of now, no official dates have been presented so all the dates are tentative/speculations in accordance to the previous years

24 Jul, 2019 (Tentative) Application - Start Date | Mode: Online

02 Aug, 2019 (Tentative) IB ACIO Tier 1 - Admit Card - Tier I | Mode: Online

15 Aug, 2019 (Tentative) IB ACIO Tier 1 - Exam - Tier I | Mode: Online

regular updates are presented in the link given below

https://competition.careers360.com/exams/ib-acio