I purchased tickets online. I just realized the date was wrong. What should/could I do? I can change the date or are tickets good for a few days or is it a loss?

Thank you for your answers! I'll call them and see what they can do about this.

Call ! The are very flexibe!

Im sure they still can change it for you, just call them

Call the museum directly. Unless you picked a specific date, the tickets should be good for a while.