Have an American Airlines flight or trip credit that you need to use? Here's a step-by-step look at how to use American Airlines flight credit and trip credits.

Year to date (YTD) refers to the period beginning on the first day of the current calendar or fiscal year and extending up to the current date.

You may have received a Delta Air Lines flight credit if you canceled a flight recently. Here's how to locate your Delta eCredit refund and use it to rebook.

The maturity date is when a debt comes due and all principal and/or interest must be repaid to creditors.

Using relative and radiometric dating methods, geologists are able to answer the question: how old is this fossil?