But concerning the times and the seasons, brothers, you have no need that anything be written to you.
The phrase "the day of the Lord" also refers to the Second Coming of Christ (cf. Joel 3:9-16; Zechariah 14:1-5; Revelation 16:12-16; Revelation 19:11-21); it includes that event between the Tribulation and the Millennium. Thus Scripture uses the term in a broad sense (the Tribulation and the Millennium) and a narrow sense (the return of Christ).