A couple tools I’ve used to help keep me honest for this sort of an event and something I’ve been using in general to track how much time I put into a project.

Time you work in a project over time. (2 weeks max for free version) https://wakatime.com/

Time you spend per day in a app. https://www.rescuetime.com/

Pomodoro tracking tool https://pomodoneapp.com/