class Date

def to_s(format = NOT_SET) # :nodoc:
  if formatter = DATE_FORMATS[format]
    ActiveSupport::Deprecation.warn(
      "Date#to_s(#{format.inspect}) is deprecated. Please use Date#to_fs(#{format.inspect}) instead."
    )
    if formatter.respond_to?(:call)
      formatter.call(self).to_s
    else
      strftime(formatter)
    end
  elsif format == NOT_SET
    if formatter = DATE_FORMATS[:default]
      ActiveSupport::Deprecation.warn(
        "Using a :default format for Date#to_s is deprecated. Please use Date#to_fs instead."
      )
      if formatter.respond_to?(:call)
        formatter.call(self).to_s
      else
        strftime(formatter)
      end
    else
      to_default_s
    end
  else
    ActiveSupport::Deprecation.warn(
      "Date#to_s(#{format.inspect}) is deprecated. Please use Date#to_fs(#{format.inspect}) instead."
    )
    to_default_s
  end
end