@rfries - I'm with @thankful and @starfirey2k on the recording hours of usage for the CPAP or BiPAP machines. I'm pretty sure they just record total usage based on a 24 hour period using the date/time on your CPAP/BiPAP machine. If you really want to see all of the data you may be interested in reading through the following discussion - Want to see all the data stored on your CPAP machine's SD Card?: https://connect.mayoclinic.org/discussion/want-to-see-all-the-data-stored-on-your-cpap-machines-sd-card/