180 days, as with the ADRs (it's option 4 on the Disney UK phone line).
And if you want them, please do book as far ahead as you can. There were quite a few folk recently who couldn't get a viewing booked at the last minute so it seems that more people are taking up this offer
I'll try and get them booked within the next couple of days then
And sorry, some more questions: where are the actual areas for preferred viewing? Is it worth booking? And is there a limit on how many nights you can book it for? I was hoping to book it twice for Wishes and twice for IllumiNations.
Unfortunately you can only book one of each per trip. Here is another thread from a few weeks ago which has more questions and info on the two locations.
MK is a bit hit and miss. Epcot I still feel is worth it