What determines when the queue is closed to new submissions?

[sly needle]

I don't mean to be annoying about it, but sometimes it closes at 14,000 submissions, sometimes 13,500, but right now there's almost 17,000 submissions and it's still open. Because of AREDL+ submissions pushing mine farther back, the only time that my submissions make any progress towards being accepted/denied is when the queue is closed. I don't want this post to be me whining and asking you to close the submissions so mine can be looked at or anything like that, but I do want to know what decides the point that the queue is closed so I can understand it better and maybe know what to look out for about when it'll close next.

[fast shell]

hi, the queue is staying open at the moment
all of us understand how big the queue is and we’re doing our best to get it lowered
whenever we check submissions we get through aredl+ records quickly and check oldest records