Can we know the day or month the Lord comes for the church?
No, the day or month of the Lord's coming for the church cannot be known. It is an imminent return, and dates must not be set. The only certainty given is that the rapture occurs when the last person is saved and the Body of Christ is completed, at the fullness of the Gentiles.
Les teaches that the word "until" is a time word, and Israel remains spiritually blinded in part until the fullness of the Gentiles is brought in. That fullness is the Body of Christ. He explains that while no one can know the day, month, or year of the Lord's coming for the church, the rapture will take place when the last person has been saved and completes the body. It is an imminent return, so dates are never to be set, but the completion of the Body of Christ is the "until" that ends Israel's blindness.