I tried to change my Meta Stack Overflow username today, and it said I have to wait 30 days between changing names:

Display name may only be changed once every 30 days; you may change again on Apr 7 at 1:19

I have never changed my username, obviously - what's going on?

Oh yeah, and I tried to change it to "minitech η". This is my new username for reference even if I can't currently change it.