Sometimes when you launch Planboard from a saved Bookmark or Favourite on your browser, it can often go to a past date in your schedule. It may be that your bookmark includes the date you saved your bookmark in it (e.g. https://planboard.chalk.com/day/2017/11/06).
If you edit the bookmark to remove the date portion it will always open up to the current day (e.g. https://planboard.chalk.com/day).
For up to date information on how to edit your Chrome Bookmarks, visit this link.