My recollection is that by default the FSS permits up to 2 years (~700 days) between services. When either days or mileage counts down, you get the message. I've never seen the days remaining message on either of my 210 cars, and I don't put many miles on them. The current (2001) car gets a service once per year, which is well before the mileage count runs out.

I know the dealer can change the default 10K miles to which the FSS resets. I'm guessing they can also change the default time between service visits. I wonder if a dealer changed the values, either at the request of an OCD previous owner, or as a semi-unscrupulous way to generate more service visits?

- JimY