Getting Your Work Hours Actually Right
I spent three years managing a team of twelve developers before I accepted that spreadsheets were killing us. We'd try to track billable versus non-billable time, but the data always felt off. What ended up working wasn't some enterprise platform either. It was Tresors Du Temps, a time management system that sounds clunky until you actually use it for a few weeks. Tresors Du Temps is a French-origin time tracking and scheduling methodology that emphasizes granular control over how you allocate hours across projects. Unlike tools that just count minutes on a clock, this approach forces you to categorize every block of time before you commit to it. You define your projects, assign hourly allocations, and then track actuals against those projections. The output is a pretty accurate picture of where your labor is going. It works best when you already know your approximate project load. If you're flying blind with no idea how many hours a week a client will need, the system gives you false precision that looks impressive but isn't useful.
Setting It Up Without Wasting Two Days
Most people overcomplicate the initial setup. Here's what actually matters in the first thirty minutes. Create your project list first. Not your time entries, not your categories. Just the projects. Give each one a short code that you'll actually remember when you're entering data at 11pm after a long day. "Project_Alpha" dies in two weeks. "PA" survives. Next, set your standard week boundaries. Decide whether you're tracking Monday-to-Friday or a rolling seven-day period. This decision matters more than people admit because it determines how your overtime calculations land. I recommend Monday-to-Friday if your team works standard business hours. Anything else creates reporting headaches later.
Then build your time categories. You need at least three: billable, non-billable internal, and administrative. Everything else gets filed under one of those. I've seen people create seventeen categories and then spend more time filing time than actually working. That defeats the whole point. The interface itself is straightforward once you accept its quirks. There's a main entry screen where you log hours, a project management view, and a reporting dashboard. The reporting dashboard is where most people give up because it takes about a week of actual data before it becomes readable. Don't abandon it during that first week.
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The Edge Case Nobody Warns You About
Here's something I learned the hard way. Tresors Du Temps assumes your projects have fixed hour budgets. When I had a client who kept scope-changing mid-sprint, the system would report that I was dramatically over budget and then I'd realize I hadn't updated the project allocation. The data was technically correct but operationally useless. The workaround is simple but not obvious. Add a twenty percent buffer to every project allocation from day one. Instead of logging 160 hours for a project, log 192. This accounts for the inevitable scope creep without requiring constant budget updates. You'll still know when you're truly over because the buffer won't absorb real overruns. Another problem: the export function only produces CSV files by default. If your finance department needs something in a different format, you'll be manually transforming data. I write a simple Python script that pulls the CSV and reformats it into whatever my accounting team requires. Took me about forty minutes to build and now it runs in about three seconds whenever I need it.
Common Mistakes That Waste Time
People enter time at the end of the day instead of in real-time. This sounds efficient but produces worse data because you forget the small tasks. Those five-minute Slack responses and quick calls add up to three or four hours a week when you account for them honestly. Log as you go or accept that your numbers are wrong. Another mistake is creating too many projects. If you have twenty active projects but only three are generating revenue, the other seventeen are noise. Merge them into broader categories until you have fewer than ten active entries. The system performs better with less clutter.
When Tresors Du Temps Fails You
This isn't a universal solution. If your team works across multiple time zones with rotating schedules, the rigid weekly boundary structure becomes frustrating. You'll spend more time adjusting entries than tracking them. For larger organizations with fifty or more employees, the reporting becomes a bottleneck. The dashboard doesn't aggregate team data well without manual intervention. In those cases, something like Harvest or Clockify handles scale better even if they lack the same categorization depth. The cost is minimal but not zero. The basic version handles individuals and small teams. Advanced reporting features require a paid tier that runs around ten dollars per user monthly. For a solo consultant this is fine. For a growing agency it adds up quickly compared to free alternatives.
Download and Access
You can find Tresors Du Temps through their official site at tresorsdutemps.com. They offer a fourteen-day free trial before requiring payment. The download is available for both desktop and mobile. Mobile sync works but occasionally lags by a few hours depending on your connection. This rarely matters unless you're submitting timesheets daily. The setup guide on their site is adequate but assumes you already understand time tracking concepts. If you're new to this entirely, watch a couple of tutorial videos on YouTube first. The learning curve is shallow but the mental model behind it takes a moment to click.
Bottom Line
Tresors Du Temps is solid for small teams who want discipline around their time without enterprise complexity. It rewards consistency and punishes procrastination. If you're going to use it, do it honestly from week one. Fake entries or lazy logging will make the reports useless faster than any software limitation ever could.
