Absent a union agreement, employment contract or existing company policy allowing for taking off on national holidays, an employer can mandate the days that employees do or do not work, with or without pay. Since PTO is provided at the discretion of an employer this means that employers are not obligated legally to give them. Consequently, they have a great deal of discretion if and when such time may be taken by an employee.The fact is an employer has a great of latitude in setting the terms and conditions of employment. For thir part, an employee can either comply or quit, their choice. This is known as "at will" employment.