Now that I've said that, here's the answer to the question I think people are trying to ask me... It depends on the year.
Sometimes we've had a schedule all summer (like the year when Emily grasped long-division in April - we were NOT taking the summer off and starting again at square one) - one where we do math once or twice a week almost all summer. Sometimes we just have a few subjects to finish up in June, so we might plan to do schoolwork two or three mornings a week until it's completed.
Other summers, it's all about getting 4-H projects completed, so we stick with our traditional "Memorial Day or earlier" guideline and close the books early. There were a couple summers when I needed the break, so we didn't do ANYTHING book related (except the summer reading program at the library) from Memorial Day to Labor Day.
Every summer is different, but we DO make sure the girls have a lot of down time in the summer. Especially now that they're older, they need a mental break. They also enjoy being able to focus on things that interest them. Arlene loves helping in the garden (and eating the strawberries) and Emily likes drawing miniature superhero pictures for her friends (they're really cute!)
Each family needs to evaluate their children's needs before making a hard and fast decision about what to do with their summer time. I grew up going to public school and always enjoyed the summers off, well, except for weeding the garden (which I now do to relax,) and we want to enjoy time outdoors with our girls. It seems not that long ago they were little, and this Fall we'll have TWO High-schoolers!
Typically our year runs from the Tuesday after Labor Day to the second or third Friday in May. This year we set a plan to stay focused through Memorial Day because of taking time off when Kurt was sick.
So, what about this year? It's a little of both worlds. We'll be working on a few review items for The Old Schoolhouse's "Schoolhouse Review Crew," Emily will be working on Algebra, and both girls are working on their 4-H projects. But mostly- we'll be taking the summer off. Come visit us at Conner Prairie - we'll be there a lot!