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.
All Visa credit cards start with a 4, MasterCard with a 5, and 6 is dedicated to Discover. The first six digits of your card, including the industry identifier, represent the issuer identification number. This identifies the bank that issued the card. And then, of course, there's your personal account number. This is made up of the seventh digit on -- everything except the last number on your card. The final digit on your credit card is known as the check digit or checksum.. This number is set by something called the Luhn formula, patented by Hans Peter Luhn, an IBM scientist in 1960. It's a formula that uses the numerals in your card's account number to verify that it's valid.