Did man invent time?

i have been reading a novel in which this idea was brought up...
it was about a plane crash and the rescue procedures... and the main female character wondered why did man invent time....
so that made me think... Did man invent time?
i came up with this thought... man invented the segments of time to which we refer... man divided time into weeks and days... man divided time into seconds and hours.... man gave time a physical meaning... something we can measure....
but time had a metaphysical meaning even before man was smart enough to know it...
but the question is... why did man tear life-up into smaller segments....
Have not you ever been late for something and wished you had just one more minute...
have you never been in an exam and felt that time is passing faster than it usually does?
or waiting for something and thought the clock might be stuck or something?
yes, man invented portions and divisions of time... but the invention really required is... a potion that makes our nerval systems respond to those divisions equally...
man divided time to hold on to the most of life as much as possible...
prehistorically, people were born, people lived, ate, drank, mated and died... they didn't know and didn't care how old any of them was or how long they lived...
they didn't record who the eldest person on earth was and put it in Guineas.
as time went by, and during ages when life mattered more than just eat and mate... or so we thought... how long and how longer meant two different things...
to live to the maximum is what matters now not to just survive...
so we have to grap life to the maximum divisions of it...
it's not that much important for normal people if a nanosecond means one over ten to the power minus 9 part of a second...
people divided time in order to find excuses why they didn't do what they had to do...
"Why didn't you finish your homework?"
"there's only 24 hours a day!"
people divided time to escape the truth...
"Why didn't you finish your homework?"
"I was playing with my pals"
people divided time to...create things they can regret and forget easily...
if only we have much time,we'd have studied better...
but there's always next year, next semester, next millennium,...
excuses, lies, regrets and easy ways out... tomorrow is another day...
but what is tomorrow ?
what is yesterday?
time... in fact... as i figured it out...is just but smaller parts of us...
if days really measured how long we lived... then, seconds and hours are pieces of us... slipping away ... like grains of sand in our palms...
but memories... r more solid parts of us... they never slip away... and from which there's no hiding place... like my favourite song says...