Originally Posted by progniss
If you bought the account from Yanli, then he made you an account with a Child's KSSN. To prevent MMOholic Kids from killing themselves by staying up all night, South Korea passed a law that prohibits game companies from offering their services to children between 12 - 6 AM GMT+8.
^ Use this link to compare the timezones between cities to find out when you can and cannot log in. Use Seoul as a reference.