At the eleventh hour
Definition 1 of 1
Pro Tip 1/3Procrastination
The phrase often indicates delaying action until the last moment, usually due to procrastination. 
He started studying for the exam at the eleventh hour.
Pro Tip 2/3Urgency Sense
Creates a sense of urgency or a dramatic effect, emphasizing the last chance to act. 
The deal was closed at the eleventh hour.
Pro Tip 3/3Possible Delays
Can imply potential delays or extended waiting before an action. 
The flight was canceled at the eleventh hour, leaving passengers stranded.