A friend of mine swears that Microsoft Excel does everything that an attorney needs to properly bill his clients. I am a big fan of Excel, however, I am not sure that it is the perfect solution. Further, I am sure that it is not the right solution for many attorneys.
However, I am a big believer in people making better use of the technology they already own before they spend money buying new technology. I have found very few attorneys who even open Excel, let alone use any of its powerful capabilities.
Esquire|Mac has a great post explaining how he uses Excel to keep track of his time. I urge you to check out his post for two reasons. First, he has a template available in the post that allows you to be up and running using Excel to keep track of your time. Simply download the template and store it with your other Excel templates.
Second, in his post explains the process he went through to write the formula that he uses in the template that he created. Reading through the post gives you an idea of just some of the things that you can do with Excel. Admittedly, if you have not worked with Excel before, most of what he has to say will sound like gibberish. However, it is a good place to start. If you follow along with what he describes, you can start to get an idea of how to put together a formula in Excel.
Also, please note that, although the template was prepared on a Mac, it still works fine on your Windows machine.