Problem statement:
It is not currently possible to insert or format dates using VisualEditor without writing them manually or using a template. This is a common tool in most text-editors for the past decade, e.g. Notepad, MS-DOS Editor.
Use Case:
As an editor, when writing a document about present, past or conceivably future events one needs to insert a date.
As an editor, when writing a document one may need to reformat the inserted date (e.g. change from ISO 2010/01/01 to 01 January 2010)
As an editor, when writing a reference, often the current date is entered as the retrieval date because websites sometimes go down, and it is useful to have a reference point.
Suggestions:
Datetime tool - This would be a standard dialog to choose a date, and its format, see Libreoffice
A simple button that inserts text containing the current client date using javascript (and ISO standard date), the user can later change this.
Tool that inserts and formats the <time> tag - see (https://developer.mozilla.org/en/docs/Web/HTML/Element/time).