Several philosophers have offered different ways of seeing that our intuition of time is not internally consistent, and may only be a construct for human interpretation, rather than something ultimately real.
McTaggart directly attacks the notion of time as an ongoing process, what he calls the A-series of events. His actual argument is a bit abstruse, but special relativity, to some degree, captures it better and backs him up. If there is no way to declare events simultaneous, then our notion of time 'unfolding' faces severe obstacles.
Kant points out in his second 'antinomy' that we do not have a firm grasp on the notion of time because we can logically prove that it both must and cannot have 'ends'. If we cannot get a handle on its basic topology, he proposes, perhaps we should back off from considering it too much of a fact.
Loschmidt's paradox suggests that the direction of the flow of time has no consistent basis because we keep finding that the principles of physics are essentially reversible. Boltzmann included this notion in his initial notions of thermodynamics, suggesting that we experience consistent time only because we are occupying a part of space relatively near an event of extremely low entropy.