How's your day, nguyen21?
Are you referring the weekly hours? If so, you can modify it by going to the Weekly Timesheet. Please see the steps below:
You may take a look with the sample screenshot below:
Once done, you can run a recent/edited Time Activities report. From there, you'll see modified history activities.
Aside from that, you can also run Time Activities by Customer or Vendor Detail Report. Lastly, I'm including an article where you can learn more about customizing report.
If you have other questions, just post it right away. I'd love to help you more with QuickBooks Online.