There was a submission from a Japanese runner with a minor issue. I want to resubmit it myself just for simplicity, but I can't do it accurately until midnight my time. Currently in Eastern Time it's August 18, but it's August 19th in Japan. I want to submit it as the 19th to keep the submission date the same, but the UI won't let me in its current form.

Probably should go here: https://www.speedrun.com/the_site/thread/g79jt

Are you talking about the date field in the run submission form, which states when the run itself was done?

Oh, thanks. But yes, that's what I'm referring to.