The three most important things for a goal are - what will be done, how will it be measured, and by when will it be done. If any of these three components are missing, then the goal is vague and we fail to hold ourselves accountable for achieving it. 

While clearly defining what will be done and how will it be measured, we bring clarity to the goal and that will help us direct our efforts better. However, it is the third component, the deadline, that actually helps us channel our efforts and prioritise the work. If I know I have to publish a document next week, I will make sure to find time during the week to get it ready to be published. 

If you're struggling to prioritise something you know is important, set a deadline. Even better if you share that deadline with others.