Period of the day starting immediately after noon and ending approximately at 6:00 p.m. The period following afternoon is called " evening ".
A: " Do you have plans for this afternoon? "
B: " Yes, I'm going to the pub at 5:00 p.m. with my friends just after class. Want to come?"
A : " Sorry I can't, I'm going to the restaurant with my girlfriend this evening at 7.p.m. "
B (looking his watch, reads 12:01 p.m.) : " That's fine! Good afternoon! "