Yes, project members can track time spent on tasks. You can learn more about it here.

What can teams do with time tracking?

1. Multiple time entries can be added for an item

2. Time entries can be associated with the user working on the project.

3. While entering time, users can give additional information about the work they did.

4. Users can mark a time entry as billable time.

5. Project admins can export time entries from a project and also from across multiple projects.

6. Users can build reports on the time spent on items (Marked for version 2 of this feature)

Note: Time tracking is available as a feature on the Pro plan.