Daniel gives the same prophecy and I look at the "Book" as those who do call on the name of the Lord, and in Christianity that is the Name of Jesus the Christ. I had felt this may have been the first century [Olivet Discourse] but it could also be future for either Daniel's people or a "type" of his people. Daniel 12:1 "At that time Michael shall stand up, The great prince who stands [watch] over the sons of your people; And there shall be a time of trouble, Such as never was since there was a nation, [Even] to that time. And at that time your people shall be saved, Every one who is found written in the book. (Young) Matthew 23:39 for I say to you, ye may not see me henceforth, till ye may say, Blessed [is] he who is coming in the name of the Lord.'