Sunrise and at dusk just not full sun. You can make a spot in the shade. Avoid any dew or fog should not be much of a problem. Pick an area small enough you can finish. If the sun is getting stronger you might work a smaller area. If you can not lay your hand on it this area might be to hot to polish ? You will just have to try a small area that you can recover and do over again if it is to hot .
The best way was developed by Mark Twain ?
Have a party get lots of help make it a fun activity.
Kind Regards. Lou