You will have a formal first sea day that night. You may not get a semi formal.
I am on the 12 night directly before yours and concierge told me on ours:-
With regards to the shows onboard the ship, we do not receive the onboard schedule in advance to know which shows will be each evening. Also, any additional shows added due to the 12-night sailing is not determined prior to sailing. Currently, the shows that are onboard the Disney Magic are All Aboard: Let the Magic Begin!, Disney Dreams: An Enchanted Classic, Twice Charmed, Villains Tonight, and Remember the Magic: A Final Farewell. We also are not provided the variety act entertainer schedule prior to sailing. We would recommend checking your Personal Navigator once onboard for any details.
Your dining rotation is not assigned until about 1-2 days prior to sailing and the information is downloaded straight to the ship. We do not receive this information from our dining team prior to sailing. You will find out your rotation when you check-in at the port. However, we do know what the three different dining rotations will be for the sailing and we can request a specific rotation on your reservation. The following are the dining rotations offered:
L - Lumiere's, A - Animator's Palate, and C - Carioca's
Rotation #1: LACLACLACLAC
Rotation #2: ACLACLACLACL
Rotation #3: CLACLACLACLA
Formal Night will be on Thursday July 23rd, the Frozen night will be on Friday July 31st, and the Semi-Formal Night will be on Saturday August 1st. Animator's Palate will feature the special interactive shows on the second and fourth night you are in Animator's Palate no matter which rotation you are scheduled on. Please let us know if you would like to request a specific rotation and we will add this to your reservation.
The current movies onboard the Disney Magic are as follows:
Finding Nemo 3D
Frozen
Maleficent
Guardians of the Galaxy
Alexander and the Terrible, Horrible, No Good, Very Bad Day
Big Hero 6
Into the Woods
McFarland USA
Cinderella
Monkey Kingdom
Avengers: Age of Ultron
Tomorrowland
Inside Out
I will be blogging live from that cruise right up to your cruise might be worth reading as I will post photos from Dover and the ships.