Photosynthesis has Light Reactions and Dark Reactions.

http://en.wikipedia.org/wiki/Photosynthesis

Photosynthesis happens 24 hours a day by the plants unlike a typical 8 hour work for a normal human being.Plants indeed do care for the perpetuation of all species on our planet.

Light Reactions

Two further compounds are generated: reduced nicotinamide adenine dinucleotide phosphate (NADPH) and adenosine triphosphate (ATP), the "energy currency" of cells.

Dark Reactions

 In the Calvin cycle, atmospheric carbon dioxide is incorporated into already existing organic carbon compounds, such as ribulose bisphosphate(RuBP).Using the ATP and NADPH produced by the light-dependent reactions, the resulting compounds are then reduced and removed to form further carbohydrates such as glucose.