copyright-year-ranges

copyright-year-ranges is a variable defined in `copyright.el'.
Its value is

nil

• This variable is safe as a file local variable if its value
  satisfies the predicate `booleanp'.

Documentation:
Non-nil if individual consecutive years should be replaced with a range.
For example: 2005, 2006, 2007, 2008 might be replaced with 2005-2008.
If you use ranges, you should add an explanatory note in a README file.
The function `copyright-fix-years' respects this variable.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.1 of Emacs.