Answer:
Then God made two great lights: the greater light to rule the day, and the lesser light to rule the night. He made the stars also. . . . So the evening and the morning were the fourth day (Genesis 1:16, 19).
Our Bible verse tells us that God made the sun, moon, and stars on the fourth day. Although the Bible doesn’t specifically say “planets,” it is correct to say that the Hebrew word translated “star” included the planets that God spoke into existence on that great day!
God also tells us that He hung these “lights” in the heavens for signs, seasons, days, and years. And another fun fact we find, as we read Genesis 1, is that the earth is actually three days older than all the stars and planets, since the earth was created on Day 1!
Source: https://answersingenesis.org/kids/astronomy/when-were-the-other-planets-created/