1. Start tracking time on cards
Open the card where you want to track time and click on the button «Time tracking».
2. Use the timer, add manual entries and set estimates
When you open the time tracking window, you can either use the timer or add manual time entries. You can also add an estimate for how much time you’re going to spend on that card. All the time that have been logged on a card will be shown as a list, with date, description, who logged it and time spent.