Time. The ever present ever watched form of measuring a day. 60 seconds make a minute.
60 mins makes an hour. Following this format 60 hours should a day make, but no 60 hours is not a day 24 hours is a day. Why. Then we go to 7 days make a week yet just 4.3 weeks approx make a month. Then 12 of these months makes a year and 365 days also make a year or so you'd think but No 365.25 days make the yrmear with every fourth year being one day longer. Seriously you'd think a toddler had made up time and how to measure it. Time was created the unit in which to measure time was created it's use in society is to complete control. If the clock didn't exist if the man made unit of measuring time didn't exist would all life stop. No it'd still go n the cosmos would still be and we would go about business as usual. It is only through man's idea of how the passage of existence should be measured that we have a clock therefore even acknowledge time as a thing. As with all things it is made from man for man to control man.
Humans are diurnal and in early days of hunting and gathering meant that making the most of your day was crucial. At night things are more difficult to accomplish and almost all creatures have a sleep cycle meaning recharge is a fact of life. With all of this need to eat daily and sleep daily and a night/day schedule productivity is a necessity. Therefore the tracking of the passage of time is a benefit. You can use many things that are good to control man, it doesn't mean they're irrelevant.
All time measures are conventionally determined.
"The base unit of time in the International System of Units (SI), and by extension most of the Western world, is the second, defined as about 9 billion oscillations of the caesium atom." Wikipedia
Time's importance to individuals is culturally determined. I had some friends that went to Liberia in the Peace Corps a long time ago. They were frustrated by the Liberian's very liberal interpretation of time: a Monday 9:30 am appointment might not actually take place until later in the week and the person making the appointment would no disagree about the initial time as it was scheduled, but rather it has to do with the relative importance of the appointment.
Many cultures act differently regarding the importance of time measures. Some are very precise, such as the Swiss, others not so much.