Chief cells ( stomuch) secreate pepsinogen , a inactivae enzyme. And in small intestine it converted into pepsin ,active form. Chief cell also present in parathyroid gland release pth harmone regulates level of calcium, magnesium, HPO4 ions in blood.
In the United States, afternoon is generally the time between noon and 5:00 p.m., and evening is considered anything after 5:00 p.m. There is no set allocation for afternoon and evening, however.
Your question as phrased gives you the answer. Afternoon begins at 12:00 noon, night begins at sunset, therefore afternoon ends when night begins. I'm not saying I agree with you, but your question gives you the answer you search. Kenneth Boos, Luckily I was ousted from Engineering career.