The quickest and easiest way to answer this is to refer to your Owners Manual or Service Manual. Most Japanese motorcycles specify to get your first service completed at 1,000km or within three months of purchasing your bike, followed by a service at 6,000kms or 6 months from your first service. From that point on it’s every 6,000kms or at 6 month intervals.
If the vehicle is used under particularly harsh environments such as remote dry desert country towns or bikes operated within close proximity of the coastal sea breezes and close to beaches/seawater then earlier service intervals are recommended to keep your motorcycle running and performing at its best and most reliable.
Servicing your bike more regularly than the manufacturer specifications is always welcomed and encouraged. Prolonging your service intervals subjects your bike not only to failing to keep within the manufacturers warranty conditions but also possibly to your motorcycle falling into a condition that can, in time have additional costs that were not necessary if it were serviced regularly.