Beyond the tracking spreadsheet
Your tracking spreadsheet is a genuinely good tool, and this page is about the three things it cannot do for you no matter how many columns you add to it.
Your spreadsheet is not the problem
It is free, it has exactly the columns you wanted, it opens on a plane, and you have refined it over several years until it fits your work better than any general project tool ever managed. None of that is nostalgia and none of it was a mistake. Anyone telling you a tracking sheet is unprofessional is selling something. The reasons to leave it are narrow and specific, and there are three of them.
A sorted list cannot show you that Thursday is already full
Rows sorted by date will tell you three jobs are due on the fourteenth. They will not tell you that the twelfth and the thirteenth are already committed, because a list has no shape and the collision only becomes obvious on a grid. Projects appear on a month view at their due date carrying the client and the language pair, colored by the stage each has reached: quoted, accepted, in progress, delivered, invoiced. A week of unconverted quotes therefore looks nothing like a week of work already under way, and that is a distinction no deadline column can make.
A quote is not yet a deadline, and delivery is not the last one
Work moves one way through those stages and the calendar follows it. A quote that never converted is cancelled and leaves the view rather than sitting there as an obligation you never took on. Delivered work stops competing for attention but stays visible until it has been invoiced and paid, because the second deadline on every translation project is the money one, and the money one is what gets forgotten, usually about six weeks after the file went out.
The feed your phone already knows how to read
Generate a subscription address once and any calendar client will read it: the phone, the laptop, the shared household calendar somebody else actually checks. Every project with a due date that has not been cancelled or paid appears in that feed, with the client's name on the entry, refreshing on the calendar's own schedule rather than on yours. Nothing has to be opened to find out whether next Tuesday is free. The address is its own credential and anyone holding it can read the feed, so treat it like a password and generate a fresh one if it escapes.
The judgement stays yours, and that is deliberate
There is no automatic capacity score here and none is planned. Nothing in a database knows that four thousand words of patent is a different week from four thousand words of newsletter, or that you already promised somebody a Saturday. What the grid does is put the due dates, the word counts and the pairs in front of you in a single look, so that answering can I take this costs two seconds instead of a reconstruction. The reconstruction is the tool's job. The answer is yours.