Follow this. Change at, or before, 8,000 km or 6 months.
It could be stretched to 10,000 km or 1 year, but that's not recommended for those who drive in severe conditions. Each vehicle's owner's manual define severe conditions differently.
The most common ones are short trips, extreme cold, hot temperatures usually above 35 C, prolong driving, etc. If you think closely, most of us fall under severe conditions. So it's better to stick 8,000 km or 6 months interval.