What's with time?

Have you ever stopped to think about why we measure time the way we do? Without machines we couldn't even keep the schedules most of us have, at least not down to the small increments we usually deem important for getting to class or work on time. Obviously days and weeks and months make sense, but seconds and minutes? Without clocks, it'd be a full time job just keeping track of what minute you're on.

What would happen if you completely confused that sense of time? How would our economy change? How would business practices change? How would sports events be effected (no, I honestly don't really care)?

Time is something we take completely for granted in this day and age, or at least, the way we interpret it, anyway.