I believe you can do the online check in when you make your final payment...the date is posted with your reservation data at the
DCL web site. We live in Oregon and find that one minute after midnight eastern time, as PrincessShmoo stated above, is correct...for us 9:01 pm. Yes, you will need a document or two printed out to take with you to check in at the ship. This process is easy. Our old printer died recently and it cost us less to buy a new one than it was costing for ink cartridges for the old printer...around $50. Good luck and enjoy your cruise!!