Owner's manual or warranty guide will instruct users to have their PMS at a recommended mileage or a fixed period, whichever comes first. Some people have two or more vehicles where one gets more mileage and use compared to the others. The less used car will reach 6 months before even hitting the target mileage.

I understand the need to have a general check-up for the vehicle every six months but do I really need to change oil as well, especially when I'm using fully synthetics and heavy duty oil filters (i.e. baldwin, fleetguard, donaldson, etc.)?

It seems to me the advancements in oil technology, like making it last for 10k km to 20k km (e.g. Mobil delvac 1) is defeated by the recommended oil change "period".