It is healthy to allow flexibility in your schedule. That being said, Sunday really depends on what you have planned for Saturday. If Saturday is a long or hard day on your legs, I would do another hard leg day on Sunday.
EDIT: If you have a hard leg day planned for tomorrow you shouldn't be doing a hard leg day today either.
"your horse is too high" - tigerchik
EDIT: If you have a hard leg day planned for tomorrow you shouldn't be doing a hard leg day today either.
"your horse is too high" - tigerchik