Did see that, but still no dice. We actually re-uploaded the attribute to coincide with the intended date style -- April 27, 2016 10:00 AM -- and Marketo is changing it to 2016-04-29 11:00:00, which is confusing. Now we're trying to set a rule to retain the intended date style.
You may also want to read this: Velocity scripts, email preview and user locale and this: Have velocity scripts to render in preview independently from the user's locale
In velocity, datetime fields will render in ISO format, while date fiels will render in a MMM dd, yyyy one.