notice period
 US /ˈnoʊtɪs ˌpɪriəd/
 UK /ˈnoʊtɪs ˌpɪriəd/

1. 
the length of time an employee or employer must give in advance if they want to end an employment contract
:
• 
My notice period is two weeks, so I'll be leaving at the end of the month.
• 
The company requires a one-month notice period for all resignations.