The Honda service manual states to adjust ignition timing every 2,400 - 3,000 miles (4,000 - 4,500 km)
We recommend setting the ignition timing with every oil change:
1,000 - 1,200 miles (1,500 - 2,000 km)
This would also include the cam chain tension and valve adjustments, which should be done before setting the ignition timing.