Every day, we are given 24 hours to spend. We can't save it. We can't borrow against it. There's no such thing as a credit card for time. Whether we're intentional about it or not, we will spend our full allotment of time each day. Our daily income and outgo of life's currency will always balance to zero.
Obviously, on the larger scale, some of us will have more time on Earth than others. But daily - unless it's your last one - we all receive the same amount.
Much like taxes, we are compelled to spend some percentage of time on food and sleep. Often, we will waste large swaths of time here or there on meaningless drivel - spending it on things we will neither remember nor care about later. Anticipating tomorrow's allotment. Promising ourselves that we'll manage our time allowance better the next go around.
But we can invest it. And that investment usually produces the best return when we give our time to someone else. Serving. Teaching. Caring. Loving. Listening. Sharing.