I have come across a useful trick today with Microsoft Notepad. It seems that this most basic of editors can help you maintain a basic time log; for example, you could use it to track the time you spend on different activities during the day.
Save this somewhere you can find it again (I chose
LOG.txt on the Desktop) and close the window.
Now add any notes underneath this to explain what you have been doing or are about to start, save and exit.
Repeat this as often as you like to build up an activity log.
Of course, there are many more sophisticated pieces of software out there to manage your time, but this is still a handy little feature from an often overlooked little program.
I have also tested this in a couple of other editors. TextPad (on Windows) offers the same feature. Gedit (Linux/GNOME) and Vim (Linux/terminal) do not. If you have tested this in any other editors, please let me know in the comments.