Are April EMH Days/Nights Set In Stone?

[Wish Upon A Star]

We would only take advantage of the EMH nights, but during our trip (because its a split trip) there aren't any MK EMH nights and the Epcot EMH nights is the first night we arrive and we won't be going to the parks that night.

Are these set in stone or will they constantly change as do the park hours?

 

[Luv4Disney]

I would pretty much bank on it. I've never had them change on me, ever. They may change month from month, but it's rare to change them once they're posted. I would count on those being the "official" days.