Who says Time has no beginning and end??
Time is how we reference change….both in measurement (the dimension of change) and in aggregate (the collective ‘flow’ of change).
So Time is abstract. It only exists in our collective minds.
Change is the underlying tangible reality.
And all change is caused by energy differential.
So there was a beginning of Time (the initial point of energy differential…Big Bang??) and will be an end of Time (the small whimper..the final exhaustion of energy differential??)