Many of us experience a high volume of work. If you do not make a plan you can be quickly overwhelmed by incoming requests and end up working reactively, rather than on the work you had planned to do. If this is you, you may feel powerless to do anything about it but using your calendar as a planning tool allows you to schedule space for the work you want to be doing, and not just the work that comes in. If you look at what you have on, you can work out what you have room for, and how likely you are to do what you promised to do.