Assume that the following two options were available, both at roughly the same time of year (early 2015) on similar ships:
1) a 7-night cruise (depart Sun. afternoon, return the following Sun. morning) from Port Canaveral (which, per JCCC3, requires a ~45 min. shuttle to/from MCO Airport for most folks, costing $50-100 round trip)
2) an 8-night cruise (depart Sat. afternoon, return the following Sun. morning) from Fort Lauderdale