Fine-tuning of accuracy

Mechanical watch has a mechanism to fine-tune accuracy,

but quartz watch can not generally fine-tune accuracy. 

However, 9F quartz of Grand Seiko can fine-tune accuracy by the switch.

Some years later after applying,

when it became clear in tendency whether it is likely to be fast or late, 

the accuracy can be compensated by the switch. 

When you use it regularly for a long period, 

you understand the "peculiarity" of the watch  

and can make adjustment to fit the "peculiarity.".