What happens once your Saturn Return is over with?

If you haven't completed certain tasks during your Saturn Return that you were suppose to finish. Does that mean once your Saturn Return is over you will no longer have the opportunity to complete them? For example I have Saturn in my 4th house. Does that mean once my Saturn Return is over with I will no longer have the opportunity to move out? I know this might seem like an odd question but this is something that I've been worried about.

If you don't learn the lessons or complete the tasks and projects you were suppose to complete during your Return once it's over should you just basically forget about making any changes?

it takes 28 years for Saturn to return to his natal position after it had hit it by transit for the first time in your life.
So a Saturn Return chart is valid for 28 years
And it`s calculated just like a Solar Return chart and any other return chart

Your Saturn return should be a time of maturation, but life is full of second chances, as other planets move through your 4th house.