Deadlines and time frames establish parameters, but typically not in a good way. The average person who is given two weeks to complete a task will instinctively adjust his or her effort so it actually takes the full two weeks.
Forget deadlines as a way to manage your activity. Look at the task and allot the time it needs to take, based on your experience, so you get it done in the right amount of time instead of the amount of time you have. Tasks should only take as long as they need to take, so do everything as quickly and effectively as you can. Then use your "free" time to get other things done--just as quickly and effectively.