Brake fluid change

[wiz 1]

Service is due on the mcs and having just read the book to see what needs doing, have found something new ,when you turn the ignition on the mileage shows when service is due but if you press the odometer button it also shows the time to brake fluid change. Got a shock as mine should have been done 400 days ago, its shown as -400. The cars just over 3 years and showing 28000 Last service 9700 when purchased 17 months ago from a main dealer. My local dealership says the fluid should be changed after 2 years surprised that a warning light hasn't come on, or when they carried out the mot recently it wasn't noticed. The cars booked in now and I'm quite relived as its quite a lot of miles in between service especially oil. Keeping my fingers crossed hoping it doesn't need anything.