1. A method of detecting a web trap, the method comprising: regularizing uniform resource locators (URLs) based on a date pattern defined in a select URL; clustering the URLs corresponding to a web page stored in a database according to a predetermined standard based on the regularized URLs; generating a regular expression by analyzing the date pattern associated with the select URL in a clustering result; and detecting at least one unwanted URL being suspected of causing an unwanted number of requests associated with linking dynamic pages of a web-based calendar by using the generated regular expression.