It is important for goals to have accomplishment dates because:

You need to set a date for ur goals so u can have a set time and say ok, i have to do this much to get this done, not having a set time gives u lots of time to do it. And if u want to have an effective goal u need to get it done.

It is imprtant for goals to have accomplishment dates because then you can see what you need to get done before the accomplishment date comes and  you can also can see what you have already done to finish everything you haven't done.