Anything that happened, even a picosecond or less ago, is in the past. What is a picosecond (or less) from now, is future. The present has no dimension in time. The duration of the present is exactly zero.
So, if it has no dimension in time, does it actually exist? How can something that has no duration at all be said to be real? It's like an object that is zero millimeters by zero millimeters by zero millimeters. Does that object actually exist?