There is a mention of Rabbi Sacks, z”lb, on the phrase חצות הלילה, which is used to describe the time at which the eldest son was killed on the night before the Exodus. Its simple translation would be midnight. Here R’ Sacks ekes out two separate deeper aspects of this statement.

The first is that G-d actually stopped time in order for this extraordinary event to take place. Now, I am not sure what this statement is based on, as I did not include that in my notes. However, before doing any research, if I took a stab at it, this is what I come up with.

• All die simultaneously on the stroke of midnight.
• Needed “time” for the Angel to reach each בכור, eldest son. If you imagine the scene literally with an angel (or even angels), wings flapping, gliding over the houses, and if there is a son, swooping down, and extinguishing his life – then you can agree that “time” was needed for that, and the night time might not have been sufficient.
• If you imagine, more esoterically, an angelic force that swept down over the people, and, identifying the houses with a son in them, as well as those protected by the blood of the lamb on the lintels, killed the eldest of the former, and passed over the houses of the latter.
• Whichever view you take, it seems that there was a time lapse wherein the angel (or angelic force) manifested in our time and our space in order to carry out its mission.
• That is, a fact—which is a truth—an essential aspect of any interaction with the entities of the Upper (& Lower) World – most commonly referred to, in our culture, as angels (& demons).
• There has to be some interaction in our world, and that takes time. Thus the Lord, in order that His mission could be completed, stopped time. Thus it would seem that all those sons did, in fact, die at exactly the stroke of midnight.

This speaks to of the idea of a higher dimensional force that was activated here. The “wave”—like the Flood—came down, and was attuned to kill all the eldest sons—except for those protected by the lamb’s blood. It still had to cover a lot of ground, and thus it needed 3d-time, though its 4d time span would have been different.

In addition, there is a midrash that says that G-d carried out the action during the 1st half of the night, while the 2nd half was the ‘effect’ of this action.

I am not sure what the meaning of that is. In addition, it seems to contradicts the previous idea of “G-d stopping time.” However, its interest to me is as an expression of the force and the effect thereof. That an event does not just consist of the event itself, but, more importantly, is the effect of the event.