a non o starts from the day you arrive ,,you have 90 days from the issue date to activate it ,,meaning to travel to Thailand ,,,so I don’t know why your trying to confuse the OP as you verified what I had said with regards activating / starting the visa
things might have changed by then haha ,,, Issa can change daily haha , retirement visa is relatively easy ,,apply for the non o to start with 90 days ,,that’s the start of it ,,good luck
some embassies ask for 6 months ,some say 3 months ,,ask London embassy direct it doesnt say anything on their web page ,,maybe they have a whats up number that does answer …a non o visa only needs to be in the day you apply ,,but that’s