Here is Tobias Dantzig, one of Einstein’s favourite mathematicians.
"Herein I see the genesis of the conflict between geometrical intuition, from which our physical concepts derive, and the logic of arithmetic. The harmony of the universe knows only one musical form – the legato; while the symphony of numbers knows only its opposite, – the staccato. All attempts to reconcile this discrepancy are based on the hope that an accelerated staccato may appear to our senses as legato. Yet our intellect will always brand such attempts as deceptions and reject such theories as an insult, as a metaphysics that purports to explain away a concept by resolving it into its opposite."
He goes on...
"The axiom of Dedekind – “if all points of a straight line fall into two classes, such that every point of the first class lies to the left of any point of the second class, then there exists one and only one point which produces this division of all points into two classes, this severing of the straight line into two portions” – this axiom is just a skilful paraphrase of the fundamental property we attribute to time. Our intuition permits us, by an act of the mind, to sever all time into the two classes, the past and the future, which are mutually exclusive and yet together comprise all of time, eternity: The now is the partition which separates all the past from all the future; any instant of the past was once a now, any instant of the future will be a now anon, and so any instant may itself act as such a partition. To be sure, of the past we know only disparate instants, yet, by an act of the mind we fill out the gaps; we conceive that between any two instants – no matter how closely these may be associated in our memory – there were other instants, and we postulate the same compactness for the future. This is what we mean by the flow of time.
Furthermore, paradoxical though this may seem, the present is truly irrational in the Dedekind sense of the word, for while it acts as partition it is neither a part of the past nor a part of the future. Indeed, in an arithmetic based on pure time, if such an arithmetic was at all possible, it is the irrational which would be taken as a matter of course, while all the painstaking efforts of our logic would be directed toward establishing the existence of rational numbers."
These words come from the second reference here, all three being worth reading on this topic.
Bell, John L, ‘Hermann Weyl on intuition and the continuum’. http://publish.uwo.ca/~jbell/Hermann%20Weyl.pdf
Dantzig, Tobias, Number – The Language of Science, (Pearson Education 2005 (1930)
Weyl, Hermann, The Continuum: A Critical Examination of the Foundations of Analysis, Dover (1987)