Hi there Sarah, welcome to planDisney!
Thank you to your father/grandfather for his service, and I love that you want to find a way to honor him. My husband served in the Air Force, and the Flag Retreat ceremony is such a special moment to experience.
The Flag Retreat ceremony takes place daily on Main Street, U.S.A. in
Disneyland Park, and it's such a wonderful moment when Guests and Cast Members will pause to honor those who have served. You can check the
entertainment schedule under "Atmosphere Entertainment" for what time it will take place each day, and my recommendation is to arrive a bit early and speak with a helpful Cast Member. When we attended the ceremony in the past, they did ask those who have served to come forward to be recognized which is wonderful. I'm sure having your family there to be with him and honor him will be a memory that will last forever!
Since this will be a multigenerational family trip, I highly recommend utilizing the
Disney PhotoPass photographers around both Disneyland Park and Disney California Adventure Park to help capture some special photos of the entire family! Some of our favorite spots for family photos include in front of Sleeping Beauty Castle in Disneyland Park, and along the water in Paradise Gardens Park in Disney California Adventure Park.
I hope this information is helpful for your upcoming trip, Sarah! If we can help with any other questions before or after your trip,
please come back and ask.
Have a magical day!
Melissa