Hello Auntie!

I have been getting aunt-ed constantly since I have turned thirty. Apparently I was merely an older sister until thirty, but having attained that noble goal, I have become an aunt. It seems I no longer have to wait for Jason and Liz to have kids, as young Japanese consider all woman over thirty aunts. This also works for men, as I have often heard shopkeepers calling older men uncle, and would assume there is a similar age marker for men. However I wonder if it happens at thirty, or do they get an extra five years, in line with the expected and suitable age for marriage?