Day of Christ is on the Day of Trumpet

In the day of Christ (εἰς ἡμέραν Χριστοῦ)

Lit., against the day, as Php_1:10. The phrase day of Christ is peculiar to this epistle. The usual expression is day of the Lord.

day of Christ. The some expression in Php_2:16. Compare Php_1:6 and 1Co_1:8; 1Co_5:5., 2Co_1:14. 2Th_2:2, where see note.

the day: Php_1:10; 1Co_1:8; 2Pe_3:10 (Day of the Lord).

Some teach that the Day of Christ is the rapture caught up in the air and the Day of the Lord is the Second Coming the last ten days before Armageddon.

Dictionary Definitions: Unger's Day of Christ: This is the period connected with reward and blessing of saints at the coming of Christ for his own. JA note: i.e. Caught up in the air (I Thess 4:17) on the Day of Trumpet (Lev 23:24-25; Matt 24:31; I Cor 15:52; I Thess 4:16-18; Rev 12:1; Rabbinic or Biblical) one year in advance (Deut 24:5; Jhn 6:39,40,44,54; Isa 34:8; 61:1-2; 63:4; Psalms 117-118) of the Day of Atonement Armageddon (Rev 14:20ff; Rev 15; Rev 16/19).

The expression occurs in I Cor 1:8; 5:5; 2 Cor 1:14; Phil 1:6, 10; 2:16. In 2 Thess 2:2 the KJV has the day of Christ incorrectly for the Day of the Lord. The Day of Christ is not the Day of the Lord. The latter (Day of the Lord) is connected with earth judgments (Rev 4:1-19:16), which will come after the out-taking of the church, the Body of Christ, and its glorification and judgment for works at the judgment seat of Christ. The Day of the Lord (Isa 2:12; Rev 19:11-21) cannot occur until after the church is completed (2 Thess 2:2-12).

Dictionary of the Bible does not have the Day of Christ but only has the Day of the Lord, the Day of Yahweh.

Wycliffe Bible Dictionary. The expression occurs in I Cor 1:8; 5:5; 2 Cor 1:14; Phil 1:6, 10; 2:16. It looks more to a moment of time than to a period of time, the moment when believers meet the Lord (in the air). It is that climatic time when the Church's pilgrimage is finished and she is joined to her Lord. It is related to believers only, and is associated with blessing, not judgment as is the Day of the Lord.

Day of God. Found only in II Pet 3:12: “ Looking for and hasting unto the coming of the day of God (Day of the Lord), wherein the heavens being on fire shall be dissolved, and the elements shell melt with fervent heat.” It is identified by some with “the Day of the Lord” spoken of in Isa 2:12-21; 13:6,9; 24-27 (cf Jer 46:10; Ezk 30:3; Joel 1:15; 2:1, 11; 3:14; Amos 5:18-20; Ob 15; Zeph 1:7, 14; Zech 14:1; Joel 2:28-32; I Thess 5:1-2; II Thess 2:2; II Pet 3:10). It starts with the events which immediately precede the second coming of Jesus Christ and continues through the Millennium on till the creation of the new heavens and the new earth. That its duration is at least a thousand years, and a thousand years as one day.