The four angels were released: the translation can be “The sixth angel released those four angels.”

Had been held ready: the form of this expression shows that it was God who had determined the exact time when these angels would be released to do the work that God had for them. For comments on the Greek verb translated held ready, see “arrayed” in Rev. 9.7.

The hour, the day, the month, and the year: it may be more natural to have something like Good News Translation, or else “the moment of that day of that very month and year.” New Jerusalem Bible has “this hour of this day of this month of this year”; Revised English Bible translates “this very year, month, day, and hour.” God had fixed the precise time of their release. However, in languages that do not have vocabulary for such precise time divisions, one may say “at this exact time.”

To kill a third of mankind: unlike Revised Standard Version and Good News Translation, it seems best to connect this purpose clause to the verb released (and not to had been held ready); so An American Translation, Barclay, Phillips, Translator’s New Testament, Biblia Dios Habla Hoy, New International Version. On the translation of third see 8.7.

An alternative translation model for languages that do not have the passive is:

• The sixth angel released those four angels to kill a third of all humans (or, people on the earth). God had kept them ready for this exact time.

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on The Revelation to John. (UBS Handbook Series). New York: UBS, 1993. For this and other handbooks for translators see here .