Added a new holiday but it doesn't reflect if someone has applied for leave

Added a new holiday but it doesn't reflect if someone has applied for leave

Hi, 

We have announced holiday for Christmas, which was not originally a part of company holiday list. 
A few people have already applied for leave during the christmas week, but now that 25th is a declared holiday I was hoping for it to reflect in the existing leave records as well, but unfortunately that is not happening. 
How can I make sure that the existing leave records are corrected?

Thanks in advance.