joeygr on "Problem with date cann't add page now"

Since a day i have a problem when i want to add a new page. When i push on publish it gives an 1: bij the publice date. Now i cann't publlish new pages and edit existing ones. How can i solve this anyone a idea? Im stuck now.

screen: http://dewebmn181.181.axc.nl/error.JPG