If time tracking is enabled Roadmap/Calendar view will show all worklog made as “clock“ icon. Once you put a mouse of it you will see the details about time logged specific date plus comment as well as total time logged for the issue.
If you want to log more time directly from the app put a mouse on intersection of the date and task to click on “plus“ icon.
A dialog will show up to log your time
You can also change the date from the dialog if you clicked on the wrong one.