And that fear has made man grow and advance, for no bird will choose to create monuments, and no dog will think to compose masterpieces, therefore, both will be forgotten.
Actually, time certainly exists, and is not an artificial construct. Man's measurement of time may be artificial, and our excessive dependence on scheduling may be limiting our ability to deal with other things, I'll grant you that. But, good luck meeting people, going to a game, or doing much else if you refuse to acknowledge that we do certain things by the clock and calendar.
HEY YOUNGBLOOD, DOESN'T IT FEEL LIKE OUR TIME IS RUNNING OUT?
Time is the fourth dimension in Physics.