Hello StunnedbyGrace,
You are correct in that, they would seem to be at odds with each other and the answer to this. In 1 Thes.4:13-18 Paul gives a detailed account of the Lord's appearing where the dead in Christ are resurrected, which is immediately followed by the living believers being changed and caught up. Now regarding that event Paul says the following:
"Now, brothers and sisters, about times and dates we do not need to write to you,
2for you know very well that the day of the Lord will come like a thief in the night."
The dates and times that Paul refers to must refer back to the subject that he was just speaking about, which is the information regarding the gathering of the church. Notice also that he refers to that event as "the day of the Lord." That said, the gathering of the church is what initiates the day of the Lord, which is then followed by the indication of God's wrath in the next verse.
We see this same issue with what Peter says regarding the day of the Lord:
"Since everything will be destroyed in this way, what kind of people ought you to be? You ought to live holy and godly lives
as you look forward to the day of God and speed its coming. That day will bring about the destruction of the heavens by fire, and the elements will melt in the heat."
Previous to that verse, Peter describes the destruction of the earth, then he says "you ought to live holy and godly lives as you look forward to the day of God and speed its coming." It would appear that Peter is saying that we should be looking forward to the day of the Lord and speed the coming of the wrath of God, which would make no sense. But it does make sense when you understand that the gathering of the church is apart of the day of the Lord and is in fact what initiates it. Therefore, Peter is referring to the gathering of the church which is apart of the day of the Lord and which takes place first. When Peter says, "you ought to live holy and godly lives as you look forward to the day of God and speed its coming," he is speaking about the gathering of the church, which takes place first and not about speeding the coming of God's wrath. Who would want to speed the coming of God's wrath. That person would certifiable! Who would be looking forward to the coming wrath of God? So Peter is referring to what initiates the day of the Lord, which is the gathering of the church and not the wrath.
In conclusion, both Paul and Peter are referring to the gathering of the church as the day of the Lord, which takes place prior to the wrath part of the day of the Lord. Once the church has been gathered, then they will say "peace and safety" and then sudden destruction will come upon them.
I hope this clears things up. If you have anything else that seems to be a contradiction, please don't hesitate to ask. If I already know the answer I will be more than happy to share. Read 1 Thes.4:13-18 and continue through Rev.5 and take note of the fact that Paul refers to the gathering of the church as "the day of the Lord."
"For the Lord himself will come down from heaven, with a loud command, with the voice of the archangel and with the trumpet call of God, and the dead in Christ will rise first. After that, we who are still alive and are left will be caught up together with them in the clouds to meet the Lord in the air. And so we will be with the Lord forever. Therefore encourage one another with these words. (<== Referring back to this ==>)
Now, brothers and sisters, about times and dates we do not need to write to you, for you know very well that the day of the Lord will come like a thief in the night. While people are saying, “Peace and safety,” destruction will come on them suddenly, as labor pains on a pregnant woman, and they will not escape.