Remember to check with your resort too
I have several resorts with Sun/Sun weeks. Some use the calendar that was provided above. Others use the Sat/Sat schedule and then bump to the next day. 2006 is a good example of this. Since 2006 started on a Sunday this year, week 1 should be 1/1-1/8 (according to this calendar). However, Ocean Landings in Cocoa Beach (for one) says it's week 1 for its Sunday check-ins start on 1/8. That's probably because they have Sat and Sun check-ins and it's easier to keep track (week 1 on the Sat/Sat week started on 1/7)