The sun will become dark, and the moon red as blood accurately translates the meaning of the literal expression “the sun will be turned into darkness and the moon into blood.” The sun will become dark may be rendered simply as “the sun will not shine,” but a more poetic form would be “the sun will become like night.” In choosing a word for red it is important to select the precise term which is used in speaking of blood. In some languages, for example, the color area of red is divided into three parts: one designates orange and other yellowish forms of red; a second refers to light reds, including pinks; and still a third specifies dark red, shading toward purple. It is normally this latter area of color which is most appropriate.

In many languages a Day cannot “come” or “arrive.” It may “happen” or “people may arrive on that day.” Under such circumstances, one must make some adjustment in the semantic structure. Furthermore, in some languages one cannot speak of a day as “great.” It can be “important,” but not “great”—the latter being applicable only to persons.

The description of that day as a glorious Day comes from the Septuagint; the Hebrew has “fearful” or “awesome,” which became in the Septuagint “glorious.” A glorious Day is a “wonderful day” in some languages—but this quality of being “wonderful” is not in terms of the quality of the day, for example, sunshine and warmth, but in terms of the significance of the day. Hence, great and glorious really stand for the importance of the event, and in some languages the two concepts must be coalesced into one, with a compensatory expression of intensity of degree, such as “that very important day of the Lord.”

The possession of a day, for example, Day of the Lord, as suggested by the genitive usage in Greek, has no direct parallel in many languages, since people simply do not possess days. One can, however, often use “the very important day for the Lord,” but this use of “for” must not suggest that the importance is merely a matter of special interest for the Lord himself. What is important is that it is the day in which the Lord will act, that is, “that very important day for what the Lord will do.”

It should be noted that in the use of Lord there is an evident ambiguity, but an intentional one. In the Old Testament passage Lord refers to Jehovah (Yahweh), but for the writer of Acts the application to Jesus is implied (see specifically v. 36). It is, therefore, important to employ some term which can be doubly applicable, both to God as Lord (in the OT) and to Jesus Christ as Lord in these typical New Testament contexts.

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on The Acts of the Apostles. (UBS Handbook Series). New York: UBS, 1972. For this and other handbooks for translators see here .