Time travel to the future in the Quran.
18:9 Did you reckon that the dwellers of the cave and the numerals were of Our wondrous signs?
18:10 When the youths hid in the cave, and they said, "Our Lord, bring us a mercy from Yourself, and prepare for us a right direction in our affair!"
18:11 So We sealed upon their ears in the cave for a number of years.
18:12 Then We roused them to know which of the two groups would be best at calculating the duration of their stay.
18:13 We narrate to you their news with truth. They were youths who acknowledged their Lord, and We increased them in guidance.
18:14 We made firm their hearts when they stood and said, "Our Lord, the Lord of heavens and earth, we will not call besides Him any god. Had We said so then it would be far astray."
18:15 "Here are our people, they have taken gods besides Him, while they do not come with any clear authority. Who then is more wicked than one who invents lies about God?"
18:16 So when you withdraw from them and what they serve besides God, seek refuge in the cave, and your Lord will distribute His mercy upon you and prepare for your problem a solution.
18:17 You see the sun when it rises, visiting their cave from the right, and when it sets, it touches them from the left, while they are in its spacious hallow. That is from God's signs. Whomever God guides is the guided one, and whomever He misguides, you will not find for him any guiding friend.
18:18 You would reckon they are awake while they are asleep. We turn them on the right-side and on the left-side, and their dog has his legs outstretched by the entrance. If you looked upon them you would have run away from them and you would have been filled with fear of them!
18:19 Thus We roused them so they would ask themselves. A speaker from amongst them said, "How long have you stayed?" They said, "We stayed a day or part of a day." He said, "Your Lord is surely aware how long you stayed, so send one of you with these money of yours to the city, and let him see which is the tastiest food, and let him come with a provision of it. Let him be courteous and let no one take notice of you."
18:20 "If they discover you, they will stone you or return you to their creed. Then you will never be successful."
18:21 Thus We let them be discovered so that they would know that God's promise is true and that there is no doubt regarding the moment. They argued amongst themselves regarding them, so they said, "Erect a monument for them!" Their Lord is fully aware of them. Those who managed to win the argument said, "We will construct a temple over them."
18:22 They will say, "Three, the fourth is their dog." They say, "Five, the sixth is their dog," guessing at what they do not know. They say, "Seven, and the eighth is their dog." Say, "My Lord is fully aware of their number, none know them except for a few." So, do not debate in them except with proof, and do not seek information regarding them from anyone.
18:23 Do not say of anything: "I will do this tomorrow;"
18:24 "Except if God wills." Remember your Lord if you forget and say, "Perhaps my Lord will guide me closer than this to the truth."
18:25 They remained in their cave for three hundred years, and increased nine
18:26 Say, "God is fully aware how long they remained, to Him is the unseen of heavens and earth, He sees and hears. They do not have besides Him any ally, nor does He share in His judgment with anyone."