The creation of time in the early universe I have seen roger Penrose video https://www.youtube.com/watch?v=sM47acQ7pEQ. In it explains that time origins are related to the rise of mass in the early universe. In the video it relates mass from Enstein E=MC^2 to planks equation E= HF (F stands for frequency). As there was no mass in the very early universe time did not exist. So time is a consequence of the rise of energy=MASS=Frequency. 
However although particles would have no mass at rest their (kinetic) momentum must have provided mass (as it happens to the photon) in the very hot early universe (prior to the highs effect) thus time must have existed as well prior and must have risen with the development of zero mass at rest particles having momentum. 
When looking at very short lived particles or virtual particles as per quantum mechanical uncertainty, any object or process that exists for a limited time or in a limited volume cannot have a precisely defined energy or momentum. So a certain volume of space is necesary for particles to become real via their momentum, prior to this, time does not exist as there is no certainty about momentum or energy within the smaller than required space (smaller than that of the wavelenght of the particle).
Could you please let me know if the reasoning is correct
 A: 
As there was no mass in the very early universe time did not exist.

The notion of "very early" requires the existence of time; without the existence of time, what meaning does the phrase "very early" have?
Of course, time existed in the very early universe if that phrase is to have any meaning.  Put circularly, there has never been a time in which time did not exist.
As I understand Penrose's argument, if all particles are massless then there is nothing with which to 'build a clock'; nothing with which to measure time.
However, in that case, there are no rulers either.
If it is the case that no mass implies time does not exist, then it must also be the case that no mass implies space does not exist.
But this is absurd.
A: Penrose's Conformal Cyclic Cosmology has absolutely no experimental or observational evidence. In fact he and his coauthor claimed there was some evidence in the CMB and it was disproven by 3 other independent analysis. Penrose's is a great mathematical physicist, but is prone to these kinds of speculations. His conformal model simply sets the conformal scale at conformal infinity to be matched to the zero scale at the Big Bang, really not a big deal since there is only the scale factor involved. The rest is speculation. 
As for time when there is no mass, photons have energy, and that defines frequencies, and thus time. They also travel in spacetime, which still must exist to have general or special covariance. Time does not need mass. @Alfred Centauri is right.
Even in the early universe with only radiation the radiation's temperature decreased over time (the cosmological time defined by the Robertson Walker metric), and the models for that match the theory. Yes, I know, that was during inflation (and then after till matter dominance) with no mass, which was due to an Inflaton (or some other such theory), took some time. If it had not been that the universe would not be homogeneous nor would we see the kind of CMB we see. 
Fact is, we don't know what could possibly mean there is no time. 
A: 
As there was no mass in the very early universe time did not exist.

It is strongly probable that this statement is true. As Alfred Centauri points out citing Penrose in his comment, without mass there would be no clock. But when he concludes that in spite of this fact time must exist because time is a dimension of spacetimes he forgets to ask the essential question: "in whose spacetime?" 
Spacetime is relative, that means each mass particle has its own Minkowski diagram. There is no absolute spacetime. If there is no mass particle, there can be no Minkowski diagram.
There may be only one doubt: We could imagine that besides mass particles there are other phenomena in the (early) universe having a clock. In this case time could have existed without mass particles. But we have no knowledge about time without mass. By consequence, it is strongly probable that the a.m. statement is true.

However although particles would have no mass at rest their (kinetic)
  momentum must have provided mass (as it happens to the photon)

Photons have momentum energy but no mass. They have no meaningful spacetime diagram because their proper time is zero. They cannot have any clock, for photons all time is reduced to zero.

So time is a consequence of the rise of energy=MASS=Frequency.

As photons are showing, not every type of energy is providing time, but only mass energy. I do not know how exactly mass is providing time, but its frequency may play a role within this mechanism.
