The Auto Date Plugin is designed for Grav CMS and automatically adds the current date to frontmatter when creating a new page via the Admin plugin.
There's not much to this plugin, simply install it and whenever you create a new page via the admin plugin, the current date will be inserted in the frontmatter of the page and show up in the Options -> Publishing Tab. The format of the date is dependent upon the value set in system.yaml under pages: dateformat: default and if not set will use H:i d-m-Y as the date format.