When to book Disneyland trip?

[slimyslitheryslug]

We are planning on going to Disneyland etc in Florida for Easter 2019. We already know the dates we will be travelling (work restrictions). When is the best time to book? Obviously we'd like to do it as cheaply as possible. Is there some sort of cycle to the offers? I've gathered we want to have booked at least six months in advance so we can get the dining options booked as soon as they open but I don't know if it is better to book the holiday now or wait until nearer the six month mark.
Thanks

We have just booked for Easter 2018. Are you absolutely set on staying in the Disney World park? If not, staying in a villa is much cheaper. I don't know how long the offer last but at the moment you pay the price of 7 days in the Disney parks for 14 days.

Staying offsite in a villa is cheaper than Disney accommodation... BUT!
Staying onsite gives you a host of other benefits, some of which will save you money, so you need to carefully weigh up the pros and cons.
The Disney dining plan is fantastic value for money and you can only get it if you stay onsite. It can literally save you hundreds of pounds if you use it right.
Free Disney transportation to all their parks reducing the need for a hire car. It also gets you back to your hotel faster after a long day rather than the nightmare of getting to the car park and negotiating the queues to get out.
Extra magic hours, so more time in the parks when it’s quieter.
The ability to book restaurants way in advance of everyone else. This is important as reservations get booked up quickly at peak times.
The ability to book ride fast passes before everyone else.
Cashless wristband payment system saves you carrying cash around.
FWIW, I’ve done both onsite and offsite and on wins hands down for me.

If you want to get the DDP included for 'free' then you can only book certain dates in April, and the offer 'normally' comes out in April for the following year. There are rumours it won't be offered for 2019, but it is probably worth waiting until then to see what they offer and what the dates are. Apparently, April is one of the busiest times (hence the reason why the free DDP is only offered for some bits of it - the end of the month I believe), in which case it might not be best to wait. The DIBB webpage has loads of info on it. It is the best place to start research.