This feature is available in Enterprise and Ultimate editions.
Choose one of the following options to access the Timesheet page. Here, you can enter the amount of you you spend working on a work item.
Option 1. From the Sidebar
Option 2. From the My Home Menu
From the main menu, click My Home > My Views > Timesheet tab.
See Entering Time/Hours and Submitting a Timesheet for instructions on how to record the hours you work.