24 hours a day
One day is 24 hours, half of that is 12 hours.
12 hours*21 days=252 hours
This depends on the type of plant and its specific needs. Plants that require full sun will need minimally six hours of sun per day. Plants that require partial sun will need 4-6 hours of sun per day. Plants that require partial shade will need 2-4 hours of sun per day, and plants that require full shade will need no direct sunlight or no more than 2 hours per day.
about 4 hours a day or 5 hours a day
There are 24 hours in a day, no need for a decimal.
You need 5 hours or exercise a day
Habaneros and other nightshades (tomatoes, peppers, eggplants, and potatoes) are sun- and- heat-loving plants that need a minimum of 5-6 hours of strong sun per day to flower and set fruit. 8-10 hours is even better.
Strawberry plants are hearty growers and can survive in many conditions. They need roughly 6 hours of sunlight a day to grow well. Excessive sunlight is not good for strawberry plants.
Poinsettias and chrysanthemums are short day plants. They need a certain number of hours of uninterrupted darkness to cause the plant to start flowering. Poinsettias need 18 hours of darkness to trigger this. Chrysanthemums need twelve hours of darkness.
6 Hours of sleep is enough
14 hours per day.