calendar-european-date-display-form is a variable defined in `calendar.el'.
Its value is

((if dayname (concat dayname ", ")) day " " monthname " " year)

  • This variable may be risky if used as a file-local variable.

Pseudo-pattern governing the way a date appears in the European style.
Normally you should not customize this, but `calendar-date-display-form'
(which see).

You can customize this variable.