Hi James23
The fixed service reminder will count down from a nominal 10,000 miles (the figure is 15,000km which is nearer 9,300 miles) while the variable reminder would normally settle to over 20,000 miles before counting down.
There is no hard evidence to suggest that leaving oil in the engine for up to 2 years has any adverse effects but I personally always use the 507.00 spec oil and change it every year.
Cheers Spike