...Built on a modern web stack (Python/Flask backend with a responsive frontend), TimeTracker enables users to track hours, manage projects and clients, visualize data with interactive charts, and even generate professional invoices directly from tracked time. It embraces privacy and flexibility by running entirely on your own servers, ensuring sensitive business data stays under your control, and supports real-time timer persistence via WebSockets so timers continue even if the browser is closed. With support for Docker deployments and a feature set tailored to freelancers and agencies alike, TimeTracker brings professional time management workflows to open source with a polished user experience and role-based access for collaboration.