Pain from knee down... on my feet for 9 hrs. walking, bending and squatting.... when i'm at rest tends to hurt at its worst. shin and calf aches-pain?

Shin & calf: Watch out for overuse and possibility of stress fracture. Vary your activity to include time off feet, if possible. Also weight control & well arched shoes.

Orthotics & Exercise: Sometimes orthotics and cushioned shoes may help-including soft mats on the surfaces you stand on.Try to keep moving when standing. Ease into & out of your rest periods. Stretch your shins and calves during these periods if you are obese-this will contribute and so losing weight would be appropriate. Orthotics.

Pain: This sounds like a great case for orthotics. See your podiatrist and you will be , well , amazed at what can be accomplished with them.