MySQL Server Locale Support For Unicode character sets, you can define collations without recompiling by using LDML notation. See Section 10.14.4, “Adding a UCA Collation to a Unicode Character Set” . To solve this problem, you should either get a new index file or manually add the name of any missing character sets to the current file. You can force client programs to use specific character set as follows: This is normally unnecessary. However, when  character_set_system  differs from character_set_server  or  character_set_client , and you input characters manually (as database object identifiers, column values, or both), these may be displayed incorrectly in output from the client or the output itself may be formatted incorrectly. In such cases, starting the mysql client with  --default- character-set= system_character_set —that is, setting the client character set to match the system character set—should fix the problem. The locale indicated by the  lc_time_names  system variable controls the language used to display day and month names and abbreviations. This variable affects the output from the  DATE_FORMAT() , DAYNAME() , and  MONTHNAME()  functions. The  lc_time_names  value does not affect the result from  FORMAT() , but this function takes an optional third parameter that enables a locale to be specified to be used for the result number’s decimal point, thousands separator, and grouping between separators. Permissible locale values are the same as the legal values for the  lc_time_names  system variable. Locale names have language and region subtags listed by IANA (http://www.iana.org/assignments/ language-subtag-registry) such as  ’ja_JP’  or  ’pt_BR’ . The default value is  ’en_US’  regardless of your system’s locale setting, but you can set the value at server startup, or set the  GLOBAL  value at runtime if you have privileges sufficient to set global system variables; see Section 5.1.9.1, “System Variable Privileges” . Any client can examine the value of  lc_time_names  or set its  SESSION  value to affect the locale for its own connection. mysql>  SET NAMES ’utf8’; Query OK, 0 rows affected (0.09 sec) mysql>  SELECT @@lc_time_names; +-----------------+ | @@lc_time_names | +-----------------+ | en_US | +-----------------+ 1 row in set (0.00 sec) mysql>  SELECT DAYNAME(’2010-01-01’), MONTHNAME(’2010-01-01’); 2005 [client] default-character-set= charset_name Character set ’ charset_name ’ is not a compiled character set and is not specified in the ’/usr/share/mysql/charsets/Index.xml’ file •If your character set index file ( Index.xml ) does not contain the name for the character set, your program displays an error message: •If the character set is a dynamic character set, but you do not have a configuration file for it, you should install the configuration file for the character set from a new MySQL distribution. lc_time_names  does not affect the  STR_TO_DATE()  or  GET_FORMAT()  function. 10.16 MySQL Server Locale Support