Simple changes to your current name do not accompany a time limit.
If you have made a typo in your user name when you joined (underscore removal or capital letter fix), you can request to any Administrator, Staff Administrator or Assistant Admin to change your name. The time caps associated with name changes don't apply, so you may change your name from "AzTeC_MaNsIoN" to "Aztec Mansion" without the 4 month cap applying. Also, if your name contains characters that do not exist in the unicode character table, you may have your name changed to something completely different regardless of the caps.