Jesus told his disciples how to know when the time of his return was near.

Matthew 24:32-35

32 “Now I want you to learn something from this parable about how fig trees grow. In this area, when the buds of a fig tree become tender and its leaves begin to sprout, you know that summer is near. 33 Similarly, when you see all these things that I have just described happening, you will know that the time for me to return is very close [MET]. 34 Keep this in mind: All of these events will happen before all the people who have observed the things that I have done have died. 35 You can be certain that these things that I have told you about will happen. You can be more certain of that than you can be certain that the earth and sky [LIT] will continue to exist.”