Have mine done every two weeks, still look newly done when I go for next appointment (apart from the regrowth, obviously). I'm hard on my nails, and wash up, do the garden etc etc, without gloves. If I've had an especially garden-y week, the colour at the very ends does tend to 'rub' off, but only slightly, they still look fab.
not exactly the same but i am on my third round of gelish, also cured bu uv light I wash my hands at least 30 times a day (occupational not OCD) The gellish remains in salon conditon for at least 2 weeks and then you see the regrowth, i get a very shimmery pink on my fingers, so it looks vaguely natural. I think it looks acceptable for another 2 weeks after that. I use cuticle oil after hand cream 3 or 4 times a day.