Here "day" and "night" are metaphors. Jesus is comparing the time when people can do God's work to daytime, the time when people normally work, and nighttime to when they cannot do God's work. (See: [[rc://en/ta/man/translate/figs-metaphor]])
Here the "world" is a metonym for the people who live in the world. AT: "living among the people of this world" (See: [[rc://en/ta/man/translate/figs-metonymy]])
# light of the world
Here "light" is a metaphor for the true revelation of God. AT: "the one who shows what is true just as light allows people to see what is in the darkness" (See: [[rc://en/ta/man/translate/figs-metaphor]])