My son's W 204 year 2011 UK Spec indicates service due in days. When serviced and reset, the display says next service due in 365 days. How do I change it to read in km or miles? Thanks.

 

It's automatic. If you were to drive more miles/km and get closer to the next service interval, it will flip on its own. Otherwise, it will stay on the calendar days mode since, for example, engine oil and filter is supposed to be changed every 1 year regardless of mileage.