They are correct: there is no right to miss work then "make it up" some other time that week for hourly employees. Hourly employees are paid for all hours that they do in fact work; and at the same time, if they miss work (e.g. scheduled hours) can be required to use PTO they earned to cover the missed hours. Your employer, not you, determines you hours; if you miss hours they wanted you at work, they may take action for it, such as requiring the use of PTO. Your right to be paid for all hours worked and your obligation to work the hours your employer assigns are independent of each other: you could theoretically miss work entirely Monday and Tusday, then work 16 hours each Wed. through Friday and have to use 16 hours of PTO for Mon. & Tuesday while also being paid for 40 hours of straight time and 8 hours of overtime for Wed. to Friday.