The opening of the chapter is explaining which days the east gate will be shut or opened.
Revelation 21:22-25
22 I did not see a temple in the city, because the Lord God Almighty and the Lamb are its temple. 23 The city does not need the sun or the moon to shine on it, for the glory of God gives it light, and the Lamb is its lamp. 24 The nations will walk by its light, and the kings of the earth will bring their splendor into it. 25 On no day will its gates ever be shut, for there will be no night there.