If I am very much mistaken, the world-line for a singularity is parallel to the t-axis, meaning time is not progressive until the singularity “explodes”. After the Big Bang, the orientation of the universal world-line regresses toward zero, so that where we are now is whatever is the “normal” slope of the t variable (which varies throughout the universe, depending on the certainty of our current vector and gravitational gradient.
Which means to me that the timeframe of the events subsequent to the Big Bang are very dilated relative to what we are familiar with: to speak of the early femtoseconds after the Big Bang ignores the time dilation that must have been present in the early universe, those initial femtoseconds might well seem to us like zillions of years in relative time.
So there was simply no time at all relative to the original singularity. The other part, well, I might have that all mucked up. It is much easier to understand when you have had some decent acid – as long as you do not notice any squirrels nearby.