I swear it was there a week ago, but suddenly my reset button went MIA for user names. I love my current display name. but wanted to reset it. I had a friend check and they have the button to reset but mine is MIA and just says I need to wait until the 20th. to change it.
I never had that before you could always reset your name just couldn't change it.
Perhaps Linden labs changed it so you can only reset after the waiting period?