If you look at a text message thread, you normally only see the messages back and forth without knowing exact when a message was sent or received.
Now with iOS 7, you can reveal the timestamp for every single message you have sent or received in a thread. Just swipe one of the speech bubbles to the left, and see what happened. Note that, the timestamps disappear once you release your finger from the screen.
![iOS 7 - iMessage with Timestamp](https://i0.wp.com/www.kjctech.net/wp-content/uploads/2013/09/kjc-iOS-7-iMessage-with-timestamp-250x375.png?resize=250%2C375)
Never excuse, never argue about exactly when the message was sent because, seriously, I have the proof right in front of your eyes.