The Day of the Lord

There are some who maintain that the Day of the Lord will be a literal twenty-four hour day, mostly those holding to a variant of posttribulationism, as well as amillennialism. 

In contrast, the prophets often used “day” to denote the epochal time when God would break into history in glory and judgment, bringing the ungodly to account.  

In those contexts, it is clearly a figurative expression denoting an epoch of [millennial blessings, not a twenty-four hour day. 

http://www.alankurschner.com/2011/12/04/the-day-of-the-lord-is-not-a-literal-24-hour-day/

i) I agree with Alan that yom has a wider semantic range. Same applies to its NT counterparts, which carry over from OT usage.

Also, it's not the meaning of yom in isolation, but the meaning of yom in a stereotypical phrase ("day of Yahweh")–which may be idiomatic. 

ii) I think "epoch" is misleading. Even making allowance for the semantic range of yom, "epoch" has different connotations than "day." 

iii) In the OT, a "day" can denote a "time" of deliverance, judgment, disaster, &c. There it's synonymous with an "event."

iv) An interesting example is Jn 8:56, where "my day" seems to be equivalent to the inauguration of the Messianic age.

v) I don't see how amillennialism entails that the day of the Lord must be a 24-hour period. In amil theology, the following things happen when Jesus returns:

a) Christians who are alive on earth at the time of his return will be glorified.

b) Christ will decisively and finally subjugate his enemies (unbelievers).

c) The general resurrection

d) The final judgment.

I don't think amillennialism requires all those things to happen within a 24-hour interval. Rather, I think "the Day of the Lord" has an inceptive sense. If Jesus literally returns, then by definition, he will return on a calendar day. So I think the "Day of the Lord" marks a terminus ad quo, but not a terminus ad quem–in the sense of a 24-hour span of time. When will these things happen? When Jesus returns. They are time-indexed to his return. 

vi) To take one example, Scripture doesn't spell out the mechanics of the final judgment. Will that involve a past life regression in which your life is replayed like a movie? Will it select for your private sins? Will that be on display for everyone to see? Will every human be judged in that sense, or only unbelievers?

Even if it's confined to unbelievers, that's a somewhat time-consuming event, although it might be a psychological experience, like a dream, where the passage of time is accelerated. If this is a serial judgment, where everybody is judged one at a time by that process, it would be extremely time-consuming. There are billions of unbelievers, past and present, to judge. 

Perhaps separate concurrent judgments are in view. And maybe the point is not that spectators see this unfold in real time, but that there's a public record. A record that's available for viewing. For instance, consider all the things that Josef Mengele did behind closed doors. Things that view people, except his victims, ever witnessed. 

vii) I think the larger point Alan is angling at is that in amil eschatology, the final events at the Parousia are synchronized so that all these things either overlap or happen in rapid succession. They needn't be strictly simultaneous. But they cluster in a brief interval, all triggered by the return of Christ.

In premillennialism, by contrast, the same events are spaced out. That's because premils use Revelation as a chronological framework. Events must happen in that sequence. Other endtime events not recorded in Revelation are intercalated in the framework.

In amil eschatology, it could take longer than a single day. Point is, though, premil eschatology requires a lot of extra time in a way that amil eschatology does not. It's not so much that the interval can't be longer on an amil timetable, but that the interval can't be shorter on a premil timetable. 

There is, though, another sense in which, in amil eschatology, endtime events are spread out over the course of the church age. The first advent of Christ inaugurates the final phase of world history. 

So to some extent it's a question of where to put these events. When they begin. In amillennialism, the countdown begins sooner. In premillennialism, it's more backloaded. 

In amillennialism, it starts out slow but picks up speed at the end. The pace accelerates heading into the final stretch. The key events take place close in time. In premillennialism, by contrast, the countdown begins much later, but once the stopwatch clicks, there's more spacing between events.