Time is the progress of existence and events. Man's concept of time is his way to keep track of it, via clock, calendars, etc.
Is time real or a man-made concept?
I don't think we can intelligently declare that time only began to exist when man showed up to contemplate it, although we are likely the first creatures on this planet with the ability to do so..
Time, like space, light, motion, gravity, matter and heat all existed throughout the universe before and without our ability to recognize them. I would submit to you the METHODS we use to identify and measure these elements are of our own invention.
One definition of time is that time "is the relationship of things that change."
In that sense it can be considered real and the method of measurement of time is man-made.
It's real