The phrase "to extend the leave" means to make the time off from work or school longer than originally planned.
Sentences with «to extend the leave»
Place your right hand on the ground and your left hand on your hip, then extend your left leg straight out to the side at hip level. (health.com)
Without bending your knee, kick your right leg while extending your left arm out in front of you to touch your toe. (health.com)
For large companies with thousands of employees, it's common to experience hundreds of employee status changes (departures, transfers, extended leaves of absence) every year. (exterro.com)