p.s. I'm guessing you are from Brazil.
Unfortunately Brazil, unlike the rest of the world, changes its clocks at midnight - most countries change the clocks at 1am or 2am. This causes lots of problems for software developers
We use the core Joomla date picker so can you confirm if you see the same problem if you select a date on the publishing tab when creating a new article? If you do then this should be reported as a Joomla bug and not a JEvents bug,