Greetings, Lynn!
Welcome to the Disney Parks Moms Panel. You've come to the right place to get the answers to your questions!
The character dining times vary between restaurants. Some of them, like
The Crystal Palace in Magic Kingdom park, have character dining throughout the day for breakfast, lunch and dinner while others may only have characters for breakfast or dinner. In order to determine if the characters are available for a specific meal time, I would recommend taking a look at the list of
character dining restaurants and then checking each individual restaurant. Another thing to keep in mind is that some of them may have different characters for breakfast and dinner like
1900 Park Fare. Mary Poppins and friends appear during breakfast while Cinderella and Prince Charming are there for dinner.
I hope this helps and if I can answer any other questions, just let me know. Wishing you a magical vacation!
~Carrie