How Long Between Extended Fasts? Breaking the fast.

My original plan was to do an extended fast at least 20 days every 6 months. Opinions?

I have not been able to find anything that talks about how much time we need to wait before embarking on another fast.

Also, i plan on breaking my fast with orange slices, sucking out the juice. Doing juice for at least two days then moving to raw for a week.. good? I love opinions and others experience.