3 years based on Irish spouse / associations meaning related by blood or through adoption
I know this because I have been approved and invited to the July ceremony. Applied through Irish association as my mother is a naturalised Irish citizen.

Hope that helps

I have received my invitation
Approval dated 28th of may, received 2nd of june
Sent fee 2nd of June, inis received the next day
Invitation dated 19th of June, received 22nd of June.

Hope everyone who is waiting gets theirs too