The favourites feature is ideal for tasks that you're frequently adding timesheets for. 

On the right hand panel you'll see the Favourites section. Click Add, enter the task details and save. This will add the favourite to the list. You can add as many favourites as you like.

To use a favourite, just drag it and drop it anywhere onto the calendar to add a timesheet for that task.

To edit a favourite, just double click it, make your changes & save.