Assuming you are talking about traveling in the future and past, Technically yes. If we go into the cosmic scale of everything you can very easily go into the future, It will cost you a few billion dollars, and a really fast spaceship, but traveling to the future is possible.
Different gravitational pulls have different effects on the speed of time. This was proven by scientist who placed different atomic clocks at different points, starting near earth and getting farther away. Although the change was small there was a change showing that the stronger the gravity the faster time speeds up.
Take this scenario into account: You have a twin and were born on earth. Fast forward twenty years later, you are about to embark on a trip to travel just outside a black hole that has been found close to earth (hypothetically of course). You say goodbye to your family and friends and your twin and embark on your journey. As you near the black hole the gravity gets stronger and stronger, not to go over the edge you park your spaceship just outside the edge of the black hole. You stay there for what feels like a year to you. But on earth, your twin has aged 5 or even ten years.
Tada! You have traveled in the future
But traveling to the past? Not so simple. That requires exceeding the speed of light (nothing in the known universe can do that) and possibly involve the physics behind wormholes which I won't get into. Can it be done? on paper yes but for now it seems like an impossible dream.
But can it be possible? Sure, with the right minds. back then people thought the flight was impossible, but overtime airplanes were built that overtook the pull of gravity. The idea of going to the moon was the pure fantasy until the rocket overcame the gravitational pull completely. So if all those fantasies and dreams come true, why not time travel? the idea of time travel has already leaped from science fiction books to the pages of the physicist. So maybe it's not for our generations, but time travel could be possible for generations to come.