I haven't trimmed since february, and the main reason I trimmed then was to get the last of the fried/bleached/dyed hair offa my head.
I wear a lot of protective styles, and I'm natural - so even if there WERE split ends - you wouldn't be able to see them, and it would break at the nearest bend. Rather nice, that. Also, I henna every month like clockwork, and even when I did still have the dye in my hair, henna almost eliminated my splits....