There are two known methods of time travel into the future. In fact, we all use them to travel extremely slightly into the future all the time. One of the methods is to move at an extremely high speed, and the other is to be in a massively powerful gravitational field. However, the idea that you are the one traveling into the future is not exactly correct, and it leads to some bad thinking about traveling into the past.
The way that you get into the future with these two methods is through a relativistic effect known as time dilation. Basically, your clock will slow down if you are traveling at a significant percentage of the speed of light, or are in an area with extreme gravity (think black hole type gravity).
Now, what is really happening is that you are almost stopping your travel through time while everyone else is moving into the future. If they could see you in your spacecraft, you would look nearly frozen* to them as they went about their business. Once you became “unfrozen”, it would appear that you had travelled into the future, but really it was everyone else that did.
This is where the bad thinking about backward time travel comes in.
Some say that If you could travel faster than light then you would go back in time. The problem with that idea, and all other reverse time travel methods that I have seen, is that only your own clock would be going backward, and the rest of the universe would still be going forward. So you do not end up in the past at the end of your travels.
Admittedly though, I have not read every one of the proposed ideas involving wormholes or quantum effects.
So, is there a method to travel back in time? The only method I can currently conceive is some sort of reset for the universe back to a particular time, with the time traveler not being involved in the reset. Those people who believe we live in a simulation might get excited about that idea, because it makes time travel seem like it could be done with a simple click. And for all we know, we may have lived through countless resets already.
*Assuming an extreme time dilation, a lesser time dilation would lead to a slow motion effect
EconUnleashed 