@Stephen *******
a visa simply is a document stating the reason you are entering, it's good for X days permission to stay in the country, it's used up upon entry (unless it's multiple entry). To stay longer you apply for an EXTENSION of stay. From that time onward you are on an extension of your permission to stay, the reason being whatever the visa was, such as retirement. Terminology is important because different rules apply to being on a visa permission to stay stamp or on an extension permission to stay stamp. Your stamp says PERMISSION TO STAY UNTIL. It doesn't say visa until, or retirement until.