According to the RCCL website, (for FL departures), the new testing requirement reads as follows:
PRE-CRUISE TEST FOR ALL GUESTS ON SAILINGS 5 NIGHTS OR LONGER
All guests age 2 and older — regardless of vaccination status — will need to take a COVID-19 test (PCR or antigen) with an accredited test provider, such as a drugstore chain or diagnostic lab, no more than 3 days before arriving at the terminal for embarkation. Guests will need to show their negative test result upon arriving at the terminal. The results can be printed out, or can be presented on your phone, such as the email result from your test provider. Costs associated with this test are the guests' responsibility.
I called RCCL C&A for some clarification on "no more than 3 days before arriving at the terminal for embarkation." My cruise departs on 12/4. I can see how RCCL could say that the test has to be taken on 12/1, 12/2, 12/3 or embarkation day 12/4. However, I can also see where RCCL could say that you CANNOT take the test on 12/1 but it has to be on 12/2, 12/3 or 12/4. I spoke with C&A and they said that you CANNOT take the test on 12/1 (in this example) but I would have to take the PCR/Antigen test on 12/2 or later.
The rep did put me on hold to talk with someone but I could easily argue that I could take a test on 12/1 which I believe is not more than 3 days prior to embarkation. This might should like a small issue but when you are driving to the pier from far away, it can make a difference.
All that being said, my "personal math" tells me I can take the test on 12/1 but it is their ship and their rules so 12/2 it is - unless I hear otherwise.
Sometimes the easy stuff can make you scratch your head.