No more than 'matter' is a human construct. We invented systems to measure time, just as we invented systems to quantify amounts of matter. Of course those systems are not the things they measure; the systems were invented by humans, the things they measure existed without humans.

You could also say that they 'ideas' of matter, energy, and time, were created by people. If you think this undermines the reality of that which the ideas reference, then you might as well be solipsist.

In short: Time is real.

(At least the 'time' that scientists speak of.)