The lights that controlled the day are spoken of as if they were a human ruler that controlled what people do. AT: "to direct the daytime as a ruler directs a group of people" or "to mark the times of the day" (See: [[rc://en/ta/man/translate/figs-personification]] and [[rc://en/ta/man/translate/figs-metaphor]])
"to separate the light from the darkness" or "to make it light at one time and dark at another." See how you translated this in [Genesis 1:4](./03.md).
This refers to the whole day. The writer speaks of the whole day as if it were these two parts. In the Jewish culture, a day begins when the sun sets. See how you translated this in [Genesis 1:5](./03.md). (See: [[rc://en/ta/man/translate/figs-merism]])
This refers to the fourth day that the universe existed. See how you translated "the first day" in [Genesis 1:5](./03.md) and decide if you should translate this the same way.