Southwest Rapid Rewards members who wanted to take advantage of the double credits promotion have a an additional three months to do so.

Under the terms of the program, Southwest Rapid Rewards members now have until April 4 to earn double credit for flights flown between now and the April cutoff. The promotion was originally scheduled to sunset on Dec. 31. With double credits, a free award ticket is earned after four round trips.

Take note though: Rewards expire after a mere 12 months.