When employers talk vacation it's based off 8-hour business days. So 3 weeks is 15 days vacation, or 120 hours if your work days aren't 8-hour based like shift

When employers talk vacation it's based off 8-hour business days. So 3 weeks is 15 days vacation, or 120 hours if your work days aren't 8-hour based like shift work or factories where you may work 4 10hour days per week.