I would agree with you a lot more if I didn't know that every now and again, you check the time.

Time is not something that doesn't exist simply because humans decided it exists, if that were the case then language, colour and just about everything that has a name doesn't exist. I prefer to think of time as a tool rather than it not being in existence, for if we started rejecting everything on the basis of it being man made, there wouldn't be anything left (as there are very few universal laws)

PS, take no notice of the above, or this, they're all words created by man so they don't exist.