Everyone wants to be productive. That’s why there are so many productivity systems and tools out there. But what is the key to productivity? Believe it or not, the key to productivity is amazingly simple:
Actually do what you need to do
That’s it. No more, no less. Just actually do what you need to do.

There is a law in economics called diminishing returns (also called diminishing marginal returns). I believe diminishing returns also applies in many other areas of life. Understanding this law is important for your personal effectiveness.
Here is an explanation about diminishing returns from Wikipedia:

… in a production system with fixed and variable inputs (say factory size [...]

I’ve been using time tracking for some time now. Besides the benefits I wrote before, I can also see the patterns of my time usage. From these patterns there are some insights I get on how to better use my time. I hope they can also be useful for you.
Here they are:

Reduce your idle time
It [...]

Time is what we want most, but what we use worst.
William Penn
Time = life; therefore, waste your time and waste of your life, or master your time and master your life.
Alan Lakein
Time is the most valuable thing a man can spend.
Theophrastus
These quotes speak for themselves. Time is our most valuable resource, yet we often use [...]

Have you ever wonder about where your time has gone? Well, wonder no more: Rachota can help you.
Rachota is a time tracking software which I use only recently. Though I have used is for less than a week, I already feel the difference. Previously I often wonder at the end of the day: how can [...]

Here are 66 best time quotes organized by topics:
Be on time
Better three hours too soon, than one minute too late.
William Shakespeare
Time is the best teacher
Time is the wisest counselor of all.
Pericles
Time is the school in which we learn, time is the fire in which we burn.
Delmore Schwartz