You may have a spare one in a chess set that a friend gave you, or perhaps one that you bought for yourself sometime in the past but no longer require the chess clock at home. If not, you might come across one in a toy store or online. Perhaps you will have to ask the friendly members of a local chess club for some assistance, as they'll be more than happy to help you get a chess clock. and place it somewhere you will be able to observe it throughout the working day. One good example location would be to put the chess clock near your computer monitor within your line of sight. This way you can easily glance at to see the duration of wasted time compared to the duration spent working efficiency.  One for player one, 1 for player 2. Use one of the clock (we shall call it the "working hard time") to record the time in which you are working (your "productivity clock"). The other clock (we shall call it the "break time / not productive time clock") is going to be activated when you're not working, such as when you require to go to pay for some one to make you a fresh coffee, ring loved ones, use the bathroom and other examples. A good idea is to make labels for (or write with a marker on) each clock face to identify which clock face corresponds to your productive or your idle time.
Obtain the required speed-chess clock. Take the speed-chess clock to work Wind each clock up (if it is a mechanical clock that is not powered by the chemical battery, but instead by some sort of mechanical store of energy such as a coiled spring) so you know it will not slow down and give an inaccurate measurement of time, which in turn would skew your results. The speed chess clock has two clock faces.