While there isn't a single official "JAJ" event on this exact date in mainstream news, here is the most likely breakdown of those terms based on common media archival formats:
The date format for August 19, 2018 (Year-Month-Day). JAJ - Adrian 1st show - 180819 - ptct
of the performer (Adrian) from the event on 180819. While there isn't a single official "JAJ" event