About that time is another one of Luke’s vague descriptions of time, and is almost verbally identical in Greek with the indication of time in 1.15.

Prophets, of course, refers to Christian prophets, and the term is used here and in 13.1; 15.32; 21.10 (see 2.16 where the reference is to Joel, the OT prophet). It should he noticed that both here and in 21.10 the only specific thing mentioned in relation to the prophets (Agabus, in both cases) is their ability to predict a future event. In many other contexts in the New Testament, and especially in the Epistles, the term prophet refers not primarily to a person who can predict future events but to one who engages in inspired preaching. In a number of languages one may require two different terms since one expression will be applicable only to foretelling future events and may even be roughly equivalent to “diviner” or “clairvoyant.” In some instances both aspects of the prophetic function may be included in a phrase such as “one who speaks on behalf of God.” With this type of expression the context alone will indicate whether the reference is to the prediction of future events or to inspired preaching.

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 .