Illinois is in the Central Time Zone in the United States of America (USA). US Central Standard Time (CST) is 6 hours behind Greenwich Mean Time (GMT-6).
Credit Card Account Number Verification - Card Type Identification. This page provides information about identifying a credit card type from a card number's numeric range and number of digits. First digit must be a 3 and second digit must be a 4 or 7. Valid length: 15 digits. First digit must be 3 and second digit must be 0, 6, or 8. Valid length: 14 digits. Valid length: 16 digits.
Credit card numbers follow certain patterns. A credit card must have between 13 and 16 digits. It must start with: â¢ 4 for Visa cards. â¢ 5 for Master cards. â¢ 37 for American Express cards. In 1954, Hans Luhn of IBM proposed an algorithm for validating credit card numbers. The algorithm is useful to determine if a card number is entered correctly or if a credit card is scanned correctly by a scanner.