I'm expermenting with
a new schedule for school this year, and so far I really like it. 
I call it “Three On, One Off”, because we do three weeks of formal
lessons, and then take one week off.  I use the “Off” week to do
major projects around the house, while the kids do independent

Here are the things I like about it:

-Three weeks is enough time to make some significant progress in the academic studies, and get into a rhythm for school.

-I can plan three weeks of school pretty easily in one sitting, and
still be comfortably close to plan at the end of the three
weeks.   It makes a nice chunk for covering a topic in
science or social studies; so far it matches well with what our
curriculum calls for this year.

-After about three weeks of
intense lessons, Mr. Boy is ready to unwind and have some unstructured
time to process it all.  I do go at a more demanding pace during
my On weeks, knowing we will have the break at the end.  I noticed
during our break that he did a lot of pretty impressive little projects.

-We both came back to the On cycle refreshed and looking forward to more lessons, rather than tired and worn out.

-It's much easier for me to tackle significant projects if I have a
large chunk of time to work with.  I've experimented with a short
time each day, or one day a week, and that just doesn't work as well
for me.

-It's much easier for me to ignore significant
projects during my On weeks, if I know that I have a time coming soon
to attend to them.

-Many major projects, such as preparing
for the holidays or doing taxes, come at intervals that work with the
Three On, One Off time frame.

-I have time to plan ahead so
that I'm ready to go when Off week arrives, with whatever materials or
equipment or appointments in place, ready for work.  Because I
know in advance when a particular project is going to be done, I can
arrange carpools, babysitters, visits with Grandma, and so forth, to
accomodate it.

    Obviously this approach
isn't for everyone.  Some people do better if they get into a
school rhythm and stay there, and would find the Off week disruptive,
rather than refreshing and productive.  And it does eat into
summer vacation.  I include a certain amount of unschooling into
our curriculum,  but my Off week is not going to be as densely
packed with instructional days (SC requires 180) as an On week. 
If a long summer vacation were important to me, this approach would not

Anyhow, that's what were doing. So far I really like it.  As the school year progresses I will report back.

Editing to add: Also, note my oldest is only in first grade.  When
my kids are working at a higher level, and working more independently,
this approach might not be as good of a fit.  But for first grade,
it's great.

[Note for people looking for more details: 
If I have a major disruption like a family vacation or a significant
holiday, I pause the cycle and then resume where we left off.  So
this most recent cycle is going:  1st week On, camp, 2nd week On,
3rd Week On, one week Off.  It'll take us five weeks to complete
the four week cycle, due to the camping getting in the way. 
Likewise at Christmas, we have two weeks off for the holiday, which I
am leaving school- and project-free, since Mr. SuperHusband will be
home and we want to enjoy him!]