it has been stated by many scientist that time can only go one way, which is forward, and it is impossible to make it go backwords, but ofcourse the time travel presented in Chrono Trigger is somewhat different then real time travel.
If you are referring to the flow of time, then it is impossible. Time travel, however, does not involve reversing the flow of time--as that would be pointless since no one would remember anything--but stepping outside of time at one point and stepping back at another point, much like, say, going off of a highway onto a service road then going back onto the highway.
time travel is impossible, with a few exceptions.
Such as relativity, going faster than the speed of light, manipulating wormholes, ect ect.
the time travel seen in ct is mearly traveling throug worm holes, so technically they do not travel throught time in the traditional way of reversing time.
Since reversing time is by no means the traditional method of time travel, you are mistaken. They are performing a somewhat atypiical method of time travel, albiet one closer to scientific principles than most forms.
so it is traveling through time, but only when a entryway is present.
Of course it is traveling through time. I fail to see why anyone would think it was not time travel, considering they do end up in different eras and whatnot.