'Signs of the Times' in the Bible

And in the morning, It will be foul weather to day: for the sky is red and lowring. O ye hypocrites, ye can discern the face of the sky; but can ye not discern the signs of the times?

You know how to interpret the appearance of the sky, yet you can't interpret the signs of the times? An evil and adulterous generation craves a sign, but no sign will be given to it except the sign of Jonah." Then he left them and went away.