Light-dependent reactions (light reactions) 2
The metabolic steps of the Calvin cycle are sometimes referred to as the dark reactions, or fight-independent reactions, because none of the steps requires light directly.
Photosynthesis (Light Reactions) - YouTube
Nevertheless, the Calvin cycle in most plants occurs during daylight, for only then can the fight reactions regenerate the NADPH and ATP spent in the reduction Of C02 to sugar.
Dark reactions make use of these organic energy molecules (ATP and NADPH). This reaction cycle is also called Calvin Benison Cycle, and it occurs in the stroma. ATP provides the energy while NADPH provides the electrons required to fix the CO2 (carbon dioxide) into carbohydrates.