A user put a calendar Web part on a Web part page, but the Calendar displays a date in the past by default. No matter how the view is changed, it defaults to a date in the past. The users can move the calendar date to a current date, but every time they navigate to the page, the past date shows.
The issue was not with the Web part on that page at all. The user was navigating to the Web part page using a link he set up in the navigation. He copied the link after he had clicked on a date in the calendar so the link contained a query string.
Redo the link in the navigation and remove query string. It turns out nothing was broken. It was just displaying the past date because those were the instructions in the query string.