No. The law requires an employee to provide their employers with advance notice of military service, with some exceptions.
Notice may be either written or oral. It may be provided by the employee or by an appropriate officer of the branch of the military in which the employee will be serving. However, no notice is required if
- Military necessity prevents the giving of notice; or
- The giving of notice is otherwise impossible or unreasonable.
"Military necessity" for purposes of the notice exception is defined in regulations of the Secretary of Defense as “a mission, operation, exercise or requirement that is classified, or a pending or ongoing mission, operation, exercise or requirement that may be compromised or otherwise adversely affected by public knowledge.