Objection 1. It would seem that the resurrection will not be at night-time. For the resurrection will not be "till the heavens be broken" (Job 14:12). Now when the heavenly movement ceases, which is signified by its breaking, there will be no time, neither night nor day. Therefore the resurrection will not be at night-time.
Objection 2. Further, the end of a thing ought to be most perfect. Now the end of time will be then: wherefore it is said (Apocalypse 10:6) that "time shall be no longer." Therefore time ought to be then in its most perfect disposition and consequently it should be the daytime.
Objection 3. Further, the time should be such as to be adapted to what is done therein: wherefore (John 13:30) the night is mentioned as being the time when Judas went out from the fellowship of the light. Now, all things that are hidden at the present time will then be made most manifest, because when the Lord shall come He "will bring to light the hidden things of darkness, and will make manifest the counsels of the hearts" (1 Corinthians 4:5). Therefore it ought to be during the day.
On the contrary, Christ's resurrection is the exemplar of ours. Now Christ's resurrection was at night, as Gregory says in a homily for Easter (xxi in Evang.). Therefore our resurrection will also be at night-time.
Further, the coming of our Lord is compared to the coming of a thief into the house (Luke 12:39-40). But the thief comes to the house at night-time. Therefore our Lord will also come in the night. Now, when He comes the resurrection will take place, as stated above (Question 76, Article 2). Therefore the resurrection will be at night-time.
I answer that, The exact time and hour at which the resurrection will be cannot be known for certain, as stated in the text (Sent. iv, D, 43). Nevertheless some assert with sufficient probability that it will be towards the twilight, the moon being in the east and the sun in the west; because the sun and moon are believed to have been created in these positions, and thus their revolutions will be altogether completed by their return to the same point. Wherefore it is said that Christ arose at such an hour.
Reply to Objection 1. When the resurrection occurs, it will not be time but the end of time; because at the very instant that the heavens will cease to move the dead will rise again. Nevertheless the stars will be in the same position as they occupy now at any fixed hour: and accordingly it is said that the resurrection will be at this or that hour.
Reply to Objection 2. The most perfect disposition of time is said to be midday, on account of the light given by the sun. But then the city of God will need neither sun nor moon, because the glory of God will enlighten it (Apocalypse 22:5). Wherefore in this respect it matters not whether the resurrection be in the day or in the night.
Reply to Objection 3. That time should be adapted to manifestation as regards the things that will happen then, and to secrecy as regards the fixing of the time. Hence either may happen fittingly, namely that the resurrection be in the day or in the night.
Source: Summa Theologica (New Advent)