How "duration" is calculated?

Please, explain how "duration" is calculated.  I installed on a test server, but I couldn't figure out how "17h 12m 22s" is achieved on the following picture

<img width="467" height="232" alt="Image" src="https://github.com/user-attachments/assets/4b17c11e-e01c-4d0f-b6c7-adb1c16ebd6b" />