An early reference

As told by Hesiod (8th century BCE):

In the beginning, the formless confusion of Chaos brooded over the unbroken darkness. Then out of the void appeared Erebus, the unknowable place where death dwells, and Night (Nyx). Then Love (Eros) was born bringing the start of order. From Love came Light and Day. Once there was Light and Day, Gaea, the earth appeared. Gaea alone gave birth to Uranus, the god of the heavens. Uranus became Gaea's mate. Together they produced the three Cyclopes, the three Hecatoncheires, and twelve Titans.

Uranus wasn't a very good father or husband (or brother!). He hated the Hecatoncheires. He imprisoned them by pushing them into the hidden places of the earth, Gaea's womb. This angered Gaea and she plotted against Uranus. She made a flint sickle and tried to get her children to attack Uranus. All were too afraid except, the youngest Titan, Cronus.

Gaea and Cronus set up an ambush of Uranus as he lay with Gaea at night. Cronus grabbed his father and castrated him, with the stone sickle, throwing the severed genitals into the ocean. Cronus became the next ruler and ruled for many ages.

Mother Earth (Gaea) and Uranus ("heaven") begat Cronus ("time"). When Gaea made Cronus castrate Uranus, this separated heaven from earth. Then Cronus became the ruler, and thus time began.

it's about the time machines stupid...

"A time machine is a device which brings about closed timelike curves—and thus enables time travel—where none would have existed otherwise. The physics literature contains various no-go theorems for time machines, i.e., theorems which purport to establish that, under physically plausible assumptions, the operation of a time machine is impossible. We conclude that for the time being there exists no conclusive no-go theorem against time machines...There are at least two distinct general notions of time machines, which we will call Wellsian and Thornian for short..."

More than just a ghost of a machine, this time machine eats CTC's.

Our defs have changed...

There is a large body of knowledge surrounding the concept of time. Both philosophy and physics have provided foundations in our current understanding. Early discussions about time appeared in the writings of the Hebrews and the Zoroastrian Iranians. Aristotle's Physics , the arguments of Newton and Leibniz, Godel's solutions to equations of Einstein's relativity, Hawkings' public lectures, all have contributed to this body of knowledge.

Of course, only Time will tell.

There is a basis...

The common objection to time travel deals with resolving 'the paradox'. What happens to the time traveler if they journey back in time and kill their mother at birth?. Well, of course in theory, the traveler would never have been born so the journey couldn't have be made; but if the journey never occurred then the mother would be born - which means the traveler would have been born and could have made the journey - and on and on! This is the paradox.

The two most-discussed solutions to this paradox include the posit that the past is completely and irreversibly defined. This first solution, the past is totally defined, dictates everything that has happened (or as some say -needs to happen) cannot be changed. The paradox is avoided since nothing can change the timeline of history, including the attempt to kill the mother. Seems that the murderer will bungle the attempt each time. Time can't be altered, nothing changes.

The other solution is the quantum idea of parallel universes. Far more complex, it depends on an understanding (or awareness!) of the theories/laws of quantum physics. Again, the paradox is avoided, for when the traveler kills their mother, a new quantum universe is created - a parallel universe - where the mother and the traveler never existed. The original universe still remains unchanged. The prominent champion of the parallel universe theory is Stephen Hawking: http://www.hawking.org.uk/lectures/warps.html