That's probably ok, or every 6000 miles. The fully synthetic oil should cope if you forget but regular changes is the way to go. The micra sump isn't all that big and small cars are more likely to be doing short urban journeys which is harder on the oil anyway.
Hi, just replaced our k12's airfilter and a bit suprised but the apparent quality difference between the two Mann branded filters. The older red coloured one just seems so much higher quality. I actually asked Mann if I'd bought a fake but they said- not a fake that's the same quality a same...