How early can you make a reservation? Like how many months in advance?

We made one two days in advance.

We tried to make reservations, but they said they were booked. It's a fairly large facility, so we arrived at the prescribed time anyway and they had a table for us.

All Reservations are made online through the MyDisneyExperienceApp (60 days) or OpenTable. (Open)

I think it's 60 days right now.

I have made reservations there about 60 days in advance before or close to it. Not sure what the earliest is but possibly 90 days.