Zones are huge generalizations, too. They are guidelines at best, defined by the coldest "average" winter temperatures, nothing to do with sun duration or intensity. Or latitude, either. Altitude and proximity to water play a huge role in zone allocation. Here the zone lines follow the coastline because if you are near the water you stay much warmer on the cold nights.
I was protesting the idea that your tip said "Full Sun" = 6 hours of direct sun everywhere.
It just doesn't work that way. Sorry if I'm being argumentative here, but this kind of info misleads a lot of people into planting things where they shouldn't.
eg. a plant labeled "full sun" in Nebraska might want 6 hours, but in Alaska it would benefit from 14 hours of direct sun because the sun is at a pretty low angle (low intensity) even at its height in June. Same plant in New Mexico might only need 4 hours of sun to flower or fruit because the sun is so much more intense.
Another example, my orchids live in "dappled shade" under my big oak tree in the summer. IF I were to move them further and further north, they would need more and more light to bloom and grow even with equivalent temperatures and the same care because the light gets less and less intense.
You simply can't put a definition on these terms because they are different everywhere.
