Is time a fictitious concept?

Time, like speed and difference, is acknowledged as a parameter.

Since there is no set amount of time in the cosmos, where does it go is a hypothetical question.

Through his Theory of Special Relativity, Einstein disproved the idea of absolute time.

We can state that time is just a fictitious variable based on the gravitational field's mass.

Time moves more slowly as mass grows, and more quickly as mass decreases. 

Because of this, time is calculated differently on every planet in the cosmos.

Like on earth, the parameters of seconds, minutes and hours are different on other planets located in the universe.

Time is determined by the force of gravity; if there is gravity, there is time; if there is no gravity, there is no time; therefore, time travel is impossible.