Although it certainly can be used otherwise, a progress tracking system like the one Paul Silvia suggests in his book How to Write a Lot seems to work best for writing that can be open ended: by following a regular writing schedule, projects can regularly and reliably come to completion. What happens, however, if one is working under a deadline (be it self-imposed or not) and, therefore, needs to develop a writing schedule backwards from this due date?
This spreadsheet is at least an elementary attempt to provide a tool for performing such a task. Yet, one obvious limitation of this spreadsheet method is that all the writing projects are arranged serially along the completion timeline rather than allowing for working on more than one project at once.
If anyone else should find this tool useful and has refinement suggestions, I would be very interested in seeing them. These formulae appear to work on Google Docs exactly as they do on Excel when that program is operated on a Windows platform, but to my understanding, Excel calculates dates differently on Mac OS than it does on Windows, so Mac users may need to adjust this spreadsheet’s formulae.