It's only confusing because it's different from what you've been doing your entire life. The solution (hypothetically, as this will never happen in our lifetime) is a different paradigm. You could say, "I'll get that to you by COB Wednesday", and it's understood by custom that "Wednesday" means "the workday that began on Wednesday". But more likely is that you'd say, "it'll be on your desk by 06:00 on the fourth." Speech patterns would adjust.