If you encounter an error "Not eligible for leave", please do as follows:
Go to the Leave module.
Click Setup, and select Reservist Leave type.
Click on the Eligible tab.
Disable the Eligible if more than 1 month after the 7th birthday of the youngest, and click Save.
Go to Process Leave and click Initialise.
Select Leave Policy and click Next.
Select Reservist Leave and click Next.
Select the employees over and Confirm.